Shop prices configurable and new music system

README.md

@@ -14,18 +14,46 @@ Player controls:
 
 - `F3`, chat `!shop`, or client console `coop_shop`: open the rewards shop
 - Chat `!points`: print personal Score, Credits, and rank
+- Chat `!musicmute` or client console `coop_music_mute`: toggle purchased server music locally
+- Client console `coop_music_volume 0.0` through `coop_music_volume 1.0`: set music volume
 - Hold `TAB`: compare all connected players' Lifetime Scores and ranks
 
 The shop contains persistent Half-Life 2 player models and permanent bonus
-weapon unlocks. Only one bonus weapon is equipped at a time. The server checks
-all kills, balances, prices, ownership, and equipment; clients cannot award
-points or choose a price.
+weapon unlocks. Only one bonus weapon is equipped at a time. It also contains a
+Music category. Buying a song unlocks it permanently; selecting Play broadcasts
+it to all connected players. One song can play at a time, with a short cooldown
+afterward. Each player can mute or adjust the music locally.
+
+The server checks all kills, balances, live prices, ownership, equipment, and
+music playback. A purchase request contains only the item type and ID: clients
+cannot award points, submit a purchase price, or debit their own Credits.
+
+Administrators get an `Admin Prices` tab in the F3 shop. Select an item, enter a
+non-negative Credit price, and save it. The server permission-checks and persists
+the change in SQLite, then broadcasts the new catalogue to all connected clients.
+The equivalent server/admin console command is:
+
+`coop_setprice <model|weapon|music> <item_id> <credits>`
+
+For example: `coop_setprice music song_id 500`. The maximum accepted price is
+100,000,000 Credits. Existing owners retain their unlocks when a price changes.
 
 Configuration is in `gamemode/progression_shared.lua`:
 
 - `Progression.Ranks`: rank names and Lifetime Score thresholds
 - `Progression.Models`: player-model catalogue and prices
 - `Progression.Weapons`: bonus-weapon catalogue and prices
+- `Progression.Music`: music catalogue, default prices, paths, and durations
 - `Progression.MonsterClasses`: NPC classes that award points
 
+Catalogue prices are initial defaults. Once seeded, live prices come from the
+`custom_coop_shop_prices` SQLite table so in-game edits survive crashes and
+restarts.
+
+Music files are not bundled with this repository. Every server owner must supply
+the audio files referenced by their `Progression.Music` entries, place them
+under `garrysmod/sound/`, and register their virtual paths with
+`resource.AddFile` so connecting clients receive them. Keep locally supplied
+audio outside the gamemode source tree and distribute or back it up separately.
+
 Player-spawned NPCs and unknown/friendly NPC classes do not award points.

gamemode/cl_progression.lua

@@ -9,8 +9,17 @@ local shopState = {
     equippedModel = Progression.DefaultModelID,
     equippedWeapon = Progression.DefaultWeaponID,
     ownedModels = {},
-    ownedWeapons = {}
+    ownedWeapons = {},
+    ownedMusic = {},
+    prices = {},
+    isAdmin = false
 }
+local activeMusicChannel
+local previousMusicVolume = 0.7
+local musicVolume = CreateClientConVar(
+    "coop_music_volume", "0.7", true, false,
+    "Volume for music bought in the custom co-op shop (0 to 1).", 0, 1
+)
 
 surface.CreateFont("CustomCoopProgressionTitle", {
     font = "Roboto",
@@ -76,6 +85,12 @@ local function SelectItem(itemType, itemID)
     net.SendToServer()
 end
 
+local function CurrentPrice(itemType, item)
+    local price = shopState.prices[itemType .. ":" .. item.id]
+    if price == nil then price = item.price or 0 end
+    return math.max(math.floor(tonumber(price) or 0), 0)
+end
+
 local function AddText(parent, text, font, color)
     local label = vgui.Create("DLabel", parent)
     label:SetText(text)
@@ -87,8 +102,14 @@ end
 
 local function AddItemCard(layout, itemType, item)
     local isModel = itemType == "model"
-    local owned = isModel and shopState.ownedModels[item.id] or shopState.ownedWeapons[item.id]
-    local equipped = isModel and shopState.equippedModel == item.id or shopState.equippedWeapon == item.id
+    local isWeapon = itemType == "weapon"
+    local isMusic = itemType == "music"
+    local owned = isModel and shopState.ownedModels[item.id]
+        or isWeapon and shopState.ownedWeapons[item.id]
+        or isMusic and shopState.ownedMusic[item.id]
+    local equipped = isModel and shopState.equippedModel == item.id
+        or isWeapon and shopState.equippedWeapon == item.id
+    local currentPrice = CurrentPrice(itemType, item)
 
     local card = layout:Add("DPanel")
     card:SetSize(252, 292)
@@ -102,7 +123,7 @@ local function AddItemCard(layout, itemType, item)
     end
 
     local previewModel = item.model
-    if not isModel and item.weaponClass ~= "" then
+    if isWeapon and item.weaponClass ~= "" then
         local storedWeapon = weapons.GetStored(item.weaponClass)
         previewModel = storedWeapon and storedWeapon.WorldModel
     end
@@ -126,7 +147,8 @@ local function AddItemCard(layout, itemType, item)
             if IsValid(entity) then entity:SetAngles(Angle(0, RealTime() * 18 % 360, 0)) end
         end
     else
-        local noPreview = AddText(card, itemType == "weapon" and "MAP LOADOUT" or "NO PREVIEW", "CustomCoopProgressionHeading", colors.muted)
+        local previewText = isMusic and "SERVER MUSIC" or isWeapon and "MAP LOADOUT" or "NO PREVIEW"
+        local noPreview = AddText(card, previewText, "CustomCoopProgressionHeading", colors.muted)
         noPreview:SetContentAlignment(5)
         noPreview:SetPos(8, 8)
         noPreview:SetSize(236, 166)
@@ -140,8 +162,8 @@ local function AddItemCard(layout, itemType, item)
     description:SetPos(12, 202)
     description:SetSize(228, 38)
 
-    local priceText = item.price == 0 and "FREE" or (item.price .. " credits")
-    local price = AddText(card, priceText, "CustomCoopProgressionBody", item.price <= shopState.credits and colors.success or colors.warning)
+    local priceText = currentPrice == 0 and "FREE" or (currentPrice .. " credits")
+    local price = AddText(card, priceText, "CustomCoopProgressionBody", currentPrice <= shopState.credits and colors.success or colors.warning)
     price:SetPos(12, 239)
     price:SetSize(100, 22)
 
@@ -149,12 +171,24 @@ local function AddItemCard(layout, itemType, item)
     button:SetPos(112, 244)
     button:SetSize(128, 36)
     button:SetFont("CustomCoopProgressionBody")
-    button:SetText(equipped and "Equipped" or (owned or item.price == 0) and "Equip" or "Buy")
+    local actionText
+    if isMusic then
+        actionText = (owned or currentPrice == 0) and "Play" or "Buy"
+    else
+        actionText = equipped and "Equipped" or (owned or currentPrice == 0) and "Equip" or "Buy"
+    end
+    button:SetText(actionText)
     button:SetEnabled(not equipped)
     button.DoClick = function()
         button:SetEnabled(false)
         button:SetText("Please wait...")
         SelectItem(itemType, item.id)
+        timer.Simple(1, function()
+            if IsValid(button) then
+                button:SetEnabled(not equipped)
+                button:SetText(actionText)
+            end
+        end)
     end
 end
 
@@ -181,6 +215,88 @@ local function CreateCataloguePage(sheet, title, itemType, items)
     sheet:AddSheet(title, page)
 end
 
+local function SendPriceChange(itemType, itemID, price)
+    local cleanPrice = math.Clamp(math.floor(tonumber(price) or 0), 0, Progression.MaximumShopPrice)
+    net.Start("CustomCoopProgressionSetPrice")
+        net.WriteString(itemType)
+        net.WriteString(itemID)
+        net.WriteUInt(cleanPrice, 32)
+    net.SendToServer()
+end
+
+local function CreateAdminPage(sheet)
+    local page = vgui.Create("DPanel", sheet)
+    page:DockPadding(10, 10, 10, 10)
+    page.Paint = function(_, width, height)
+        draw.RoundedBox(6, 0, 0, width, height, Color(24, 29, 35))
+    end
+
+    local controls = vgui.Create("DPanel", page)
+    controls:Dock(BOTTOM)
+    controls:SetTall(70)
+    controls:DockMargin(0, 8, 0, 0)
+    controls.Paint = nil
+
+    local instruction = AddText(
+        controls,
+        "Select an item, enter its new Credit price, then save. All connected clients refresh immediately.",
+        "CustomCoopProgressionSmall",
+        colors.muted
+    )
+    instruction:Dock(TOP)
+    instruction:SetTall(24)
+
+    local priceInput = vgui.Create("DNumberWang", controls)
+    priceInput:Dock(LEFT)
+    priceInput:SetWide(180)
+    priceInput:SetMinMax(0, Progression.MaximumShopPrice)
+    priceInput:SetDecimals(0)
+    priceInput:SetValue(0)
+
+    local save = vgui.Create("DButton", controls)
+    save:Dock(LEFT)
+    save:DockMargin(8, 0, 0, 0)
+    save:SetWide(180)
+    save:SetText("Save selected price")
+    save:SetFont("CustomCoopProgressionBody")
+    save:SetEnabled(false)
+
+    local list = vgui.Create("DListView", page)
+    list:Dock(FILL)
+    list:AddColumn("Type"):SetFixedWidth(85)
+    list:AddColumn("Item ID"):SetFixedWidth(190)
+    list:AddColumn("Item")
+    list:AddColumn("Credits"):SetFixedWidth(100)
+
+    for _, catalogue in ipairs({
+        { itemType = "model", items = Progression.Models },
+        { itemType = "weapon", items = Progression.Weapons },
+        { itemType = "music", items = Progression.Music }
+    }) do
+        for _, item in ipairs(catalogue.items) do
+            local row = list:AddLine(catalogue.itemType, item.id, item.name, CurrentPrice(catalogue.itemType, item))
+            row.CustomCoopItemType = catalogue.itemType
+            row.CustomCoopItemID = item.id
+        end
+    end
+
+    local selectedRow
+    list.OnRowSelected = function(_, _, row)
+        selectedRow = row
+        priceInput:SetValue(tonumber(row:GetColumnText(4)) or 0)
+        save:SetEnabled(true)
+    end
+
+    save.DoClick = function()
+        if not IsValid(selectedRow) then return end
+        SendPriceChange(selectedRow.CustomCoopItemType, selectedRow.CustomCoopItemID, priceInput:GetValue())
+        save:SetEnabled(false)
+        save:SetText("Saving...")
+    end
+
+    sheet:AddSheet("Admin Prices", page)
+end
+
 local function OpenShop()
     if IsValid(shopFrame) then shopFrame:Remove() end
 
@@ -224,6 +340,18 @@ local function OpenShop()
 
     CreateCataloguePage(sheet, "Player Models", "model", Progression.Models)
     CreateCataloguePage(sheet, "Bonus Weapons", "weapon", Progression.Weapons)
+    CreateCataloguePage(sheet, "Music", "music", Progression.Music)
+    if shopState.isAdmin then CreateAdminPage(sheet) end
+end
+
+local function ReadShopPrices()
+    local prices = {}
+    for _ = 1, net.ReadUInt(8) do
+        local itemType = net.ReadString()
+        local itemID = net.ReadString()
+        prices[itemType .. ":" .. itemID] = net.ReadUInt(32)
+    end
+    return prices
 end
 
 net.Receive("CustomCoopProgressionOpenShop", function()
@@ -233,6 +361,7 @@ net.Receive("CustomCoopProgressionOpenShop", function()
     shopState.equippedWeapon = net.ReadString()
     shopState.ownedModels = { [Progression.DefaultModelID] = true }
     shopState.ownedWeapons = { [Progression.DefaultWeaponID] = true }
+    shopState.ownedMusic = {}
 
     for _ = 1, net.ReadUInt(8) do
         local itemType = net.ReadString()
@@ -241,12 +370,24 @@ net.Receive("CustomCoopProgressionOpenShop", function()
             shopState.ownedModels[itemID] = true
         elseif itemType == "weapon" then
             shopState.ownedWeapons[itemID] = true
+        elseif itemType == "music" then
+            shopState.ownedMusic[itemID] = true
         end
     end
 
+
+    shopState.isAdmin = net.ReadBool()
+    shopState.prices = ReadShopPrices()
+
     OpenShop()
 end)
 
+net.Receive("CustomCoopProgressionPricesChanged", function()
+    shopState.prices = ReadShopPrices()
+    if IsValid(shopFrame) then OpenShop() end
+    notification.AddLegacy("Shop prices were updated by an administrator.", NOTIFY_GENERIC, 4)
+end)
+
 net.Receive("CustomCoopProgressionNotice", function()
     local success = net.ReadBool()
     local message = net.ReadString()
@@ -254,6 +395,56 @@ net.Receive("CustomCoopProgressionNotice", function()
     surface.PlaySound(success and "buttons/button15.wav" or "buttons/button10.wav")
 end)
 
+local function ToggleMusicMute()
+    local current = musicVolume:GetFloat()
+    if current > 0.001 then
+        previousMusicVolume = current
+        RunConsoleCommand("coop_music_volume", "0")
+        notification.AddLegacy("Shop music muted. Use !musicmute to turn it back on.", NOTIFY_GENERIC, 4)
+    else
+        RunConsoleCommand("coop_music_volume", tostring(math.max(previousMusicVolume, 0.1)))
+        notification.AddLegacy("Shop music enabled.", NOTIFY_GENERIC, 4)
+    end
+end
+
+concommand.Add("coop_music_mute", ToggleMusicMute)
+
+cvars.AddChangeCallback("coop_music_volume", function(_, _, newValue)
+    if IsValid(activeMusicChannel) then
+        activeMusicChannel:SetVolume(math.Clamp(tonumber(newValue) or 0, 0, 1))
+    end
+end, "CustomCoopProgressionMusicVolume")
+
+net.Receive("CustomCoopProgressionToggleMusicMute", ToggleMusicMute)
+
+net.Receive("CustomCoopProgressionPlayMusic", function()
+    local itemID = net.ReadString()
+    local buyerName = net.ReadString()
+    local item = Progression.GetMusic(itemID)
+    if not item then return end
+
+    if IsValid(activeMusicChannel) then
+        activeMusicChannel:Stop()
+        activeMusicChannel = nil
+    end
+
+    sound.PlayFile("sound/" .. item.sound, "noplay", function(channel, errorID, errorName)
+        if not IsValid(channel) then
+            notification.AddLegacy(
+                "Could not play " .. item.name .. ": " .. tostring(errorName or errorID),
+                NOTIFY_ERROR,
+                6
+            )
+            return
+        end
+
+        activeMusicChannel = channel
+        channel:SetVolume(math.Clamp(musicVolume:GetFloat(), 0, 1))
+        channel:Play()
+        notification.AddLegacy(buyerName .. " is playing " .. item.name .. ".", NOTIFY_GENERIC, 5)
+    end)
+end)
+
 local previousScore
 local gainedScore = 0
 local gainExpires = 0

gamemode/init.lua

@@ -20,4 +20,5 @@ include( "shared.lua" )
 include( "maprotation.lua" )
 include( "sv_progression.lua" )
 
-resource.AddFile( "sound/weapons/universal/pap.wav" )
+resource.AddFile( "sound/weapons/universal/pap.wav" )
+resource.AddFile( "sound/custom_coop_music/trololo.mp3" )

gamemode/progression_shared.lua

@@ -9,6 +9,8 @@ Progression.KillReward = 1
 Progression.DeathCreditCost = 5
 Progression.DefaultModelID = "kleiner"
 Progression.DefaultWeaponID = "none"
+Progression.MaximumShopPrice = 100000000
+Progression.MusicCooldownPadding = 10
 
 Progression.Ranks = {
     { score = 0, name = "Newbie" },
@@ -145,6 +147,17 @@ Progression.Weapons = {
     }
 }
 
+Progression.Music = {
+    {
+        id = "trololo",
+        name = "Trolololo",
+        sound = "custom_coop_music/trololo.mp3",
+        price = 250,
+        duration = 162,
+        description = "Play the full song for everybody currently on the server. Unlocks permanently."
+    }
+}
+
 -- Only these combat NPC classes award points. Keeping an allow-list avoids
 -- rewards for friendly citizens, scripted targets and manually invented entity
 -- classes. Add a class here if a future coop map uses another real monster.
@@ -217,6 +230,10 @@ function Progression.GetWeapon(id)
     return FindByID(Progression.Weapons, id)
 end
 
+function Progression.GetMusic(id)
+    return FindByID(Progression.Music, id)
+end
+
 function Progression.GetRank(score)
     local result = Progression.Ranks[1].name
     score = math.max(tonumber(score) or 0, 0)

gamemode/sv_progression.lua

@@ -3,11 +3,17 @@ if not SERVER then return end
 local Progression = CustomCoopProgression
 local playerStates = setmetatable({}, { __mode = "k" })
 local requestCooldowns = setmetatable({}, { __mode = "k" })
+local shopPrices = {}
+local musicBusyUntil = 0
 
 util.AddNetworkString("CustomCoopProgressionOpenShop")
 util.AddNetworkString("CustomCoopProgressionRequestShop")
 util.AddNetworkString("CustomCoopProgressionSelectItem")
 util.AddNetworkString("CustomCoopProgressionNotice")
+util.AddNetworkString("CustomCoopProgressionSetPrice")
+util.AddNetworkString("CustomCoopProgressionPricesChanged")
+util.AddNetworkString("CustomCoopProgressionPlayMusic")
+util.AddNetworkString("CustomCoopProgressionToggleMusicMute")
 
 local function Query(query, context)
     local result = sql.Query(query)
@@ -43,10 +49,84 @@ local function CreateTables()
             PRIMARY KEY (steamid64, item_type, item_id)
         )
     ]], "could not create ownership table")
+
+    Query([[
+        CREATE TABLE IF NOT EXISTS custom_coop_shop_prices (
+            item_type TEXT NOT NULL,
+            item_id TEXT NOT NULL,
+            price INTEGER NOT NULL,
+            PRIMARY KEY (item_type, item_id)
+        )
+    ]], "could not create shop price table")
 end
 
 CreateTables()
 
+local catalogues = {
+    { itemType = "model", items = Progression.Models },
+    { itemType = "weapon", items = Progression.Weapons },
+    { itemType = "music", items = Progression.Music }
+}
+
+local function PriceKey(itemType, itemID)
+    return itemType .. ":" .. itemID
+end
+
+local function GetCatalogueItem(itemType, itemID)
+    if itemType == "model" then return Progression.GetModel(itemID) end
+    if itemType == "weapon" then return Progression.GetWeapon(itemID) end
+    if itemType == "music" then return Progression.GetMusic(itemID) end
+end
+
+local function GetShopPrice(itemType, item)
+    return shopPrices[PriceKey(itemType, item.id)] or math.max(math.floor(item.price or 0), 0)
+end
+
+local function LoadShopPrices()
+    for _, catalogue in ipairs(catalogues) do
+        for _, item in ipairs(catalogue.items) do
+            Query(string.format(
+                "INSERT OR IGNORE INTO custom_coop_shop_prices (item_type, item_id, price) VALUES (%s, %s, %d)",
+                SQLString(catalogue.itemType), SQLString(item.id), math.max(math.floor(item.price or 0), 0)
+            ), "could not seed shop price")
+        end
+    end
+
+    local rows = Query("SELECT item_type, item_id, price FROM custom_coop_shop_prices", "could not load shop prices")
+    if not istable(rows) then return end
+
+    for _, row in ipairs(rows) do
+        local item = GetCatalogueItem(row.item_type, row.item_id)
+        local price = math.floor(tonumber(row.price) or -1)
+        if item and price >= 0 and price <= Progression.MaximumShopPrice then
+            shopPrices[PriceKey(row.item_type, row.item_id)] = price
+        end
+    end
+end
+
+LoadShopPrices()
+
+local function WriteShopPrices()
+    local entries = {}
+    for _, catalogue in ipairs(catalogues) do
+        for _, item in ipairs(catalogue.items) do
+            entries[#entries + 1] = {
+                itemType = catalogue.itemType,
+                id = item.id,
+                price = GetShopPrice(catalogue.itemType, item)
+            }
+        end
+    end
+
+    net.WriteUInt(math.min(#entries, 255), 8)
+    for index = 1, math.min(#entries, 255) do
+        local entry = entries[index]
+        net.WriteString(entry.itemType)
+        net.WriteString(entry.id)
+        net.WriteUInt(math.min(entry.price, 4294967295), 32)
+    end
+end
+
 local function EmptyState()
     return {
         score = 0,
@@ -54,7 +134,8 @@ local function EmptyState()
         equippedModel = Progression.DefaultModelID,
         equippedWeapon = Progression.DefaultWeaponID,
         ownedModels = { [Progression.DefaultModelID] = true },
-        ownedWeapons = { [Progression.DefaultWeaponID] = true }
+        ownedWeapons = { [Progression.DefaultWeaponID] = true },
+        ownedMusic = {}
     }
 end
 
@@ -109,6 +190,8 @@ local function LoadPlayer(ply)
                 state.ownedModels[owned.item_id] = true
             elseif owned.item_type == "weapon" and Progression.GetWeapon(owned.item_id) then
                 state.ownedWeapons[owned.item_id] = true
+            elseif owned.item_type == "music" and Progression.GetMusic(owned.item_id) then
+                state.ownedMusic[owned.item_id] = true
             end
         end
     end
@@ -186,6 +269,9 @@ local function SendShop(ply)
     for id in pairs(state.ownedWeapons) do
         owned[#owned + 1] = { itemType = "weapon", id = id }
     end
+    for id in pairs(state.ownedMusic) do
+        owned[#owned + 1] = { itemType = "music", id = id }
+    end
 
     net.Start("CustomCoopProgressionOpenShop")
         net.WriteUInt(math.min(state.score, 4294967295), 32)
@@ -197,6 +283,8 @@ local function SendShop(ply)
             net.WriteString(owned[index].itemType)
             net.WriteString(owned[index].id)
         end
+        net.WriteBool(ply:IsAdmin())
+        WriteShopPrices()
     net.Send(ply)
 end
 
@@ -214,10 +302,70 @@ local function RequestAllowed(ply)
     return true
 end
 
-local function PurchaseOrEquip(ply, itemType, itemID)
-    if itemType ~= "model" and itemType ~= "weapon" then return end
+local function BroadcastShopPrices()
+    net.Start("CustomCoopProgressionPricesChanged")
+        WriteShopPrices()
+    net.Broadcast()
+end
 
-    local item = itemType == "model" and Progression.GetModel(itemID) or Progression.GetWeapon(itemID)
+local function SetShopPrice(actor, itemType, itemID, requestedPrice)
+    local item = GetCatalogueItem(itemType, itemID)
+    local price = math.floor(tonumber(requestedPrice) or -1)
+    if not item or price < 0 or price > Progression.MaximumShopPrice then
+        if IsValid(actor) then SendNotice(actor, false, "Invalid shop item or price.") end
+        return false
+    end
+
+    local result = Query(string.format(
+        "INSERT OR REPLACE INTO custom_coop_shop_prices (item_type, item_id, price) VALUES (%s, %s, %d)",
+        SQLString(itemType), SQLString(itemID), price
+    ), "could not save shop price")
+    if result == false then
+        if IsValid(actor) then SendNotice(actor, false, "The new price could not be saved.") end
+        return false
+    end
+
+    shopPrices[PriceKey(itemType, itemID)] = price
+    BroadcastShopPrices()
+
+    local message = string.format("Set %s to %d credits.", item.name, price)
+    if IsValid(actor) then
+        SendNotice(actor, true, message)
+    else
+        print("[custom_coop progression] " .. message)
+    end
+    return true
+end
+
+local function PlayMusic(ply, item)
+    local now = CurTime()
+    if musicBusyUntil > now then
+        SendNotice(ply, false, string.format(
+            "Music is busy. Try again in %d seconds.",
+            math.ceil(musicBusyUntil - now)
+        ))
+        return
+    end
+
+    if not file.Exists("sound/" .. item.sound, "GAME") then
+        SendNotice(ply, false, "That music file is unavailable on the server.")
+        return
+    end
+
+    local duration = math.max(tonumber(item.duration) or 0, 1)
+    musicBusyUntil = now + duration + math.max(Progression.MusicCooldownPadding or 0, 0)
+
+    net.Start("CustomCoopProgressionPlayMusic")
+        net.WriteString(item.id)
+        net.WriteString(ply:Nick())
+    net.Broadcast()
+
+    PrintMessage(HUD_PRINTTALK, string.format("[CO-OP] %s is playing %s.", ply:Nick(), item.name))
+    SendNotice(ply, true, "Playing " .. item.name .. " for everyone.")
+end
+
+local function PurchaseOrEquip(ply, itemType, itemID)
+    local item = GetCatalogueItem(itemType, itemID)
     if not item then return end
 
     if itemType == "weapon" and item.weaponClass ~= "" and not weapons.GetStored(item.weaponClass) then
@@ -225,16 +373,30 @@ local function PurchaseOrEquip(ply, itemType, itemID)
         return
     end
 
+    if itemType == "music" and not file.Exists("sound/" .. item.sound, "GAME") then
+        SendNotice(ply, false, "That music file is unavailable. No credits were spent.")
+        return
+    end
+
     local state = GetState(ply)
     if not state then return end
 
-    local ownedItems = itemType == "model" and state.ownedModels or state.ownedWeapons
-    local alreadyOwned = ownedItems[itemID] == true or item.price == 0
+    local ownedItems = itemType == "model" and state.ownedModels
+        or itemType == "weapon" and state.ownedWeapons
+        or state.ownedMusic
+    local price = GetShopPrice(itemType, item)
+    local alreadyOwned = ownedItems[itemID] == true or price == 0
     local previousWeaponID = state.equippedWeapon
 
+    if itemType == "music" and alreadyOwned then
+        PlayMusic(ply, item)
+        SendShop(ply)
+        return
+    end
+
     if not alreadyOwned then
-        if state.credits < item.price then
-            SendNotice(ply, false, "You need " .. (item.price - state.credits) .. " more credits.")
+        if state.credits < price then
+            SendNotice(ply, false, "You need " .. (price - state.credits) .. " more credits.")
             return
         end
 
@@ -247,7 +409,7 @@ local function PurchaseOrEquip(ply, itemType, itemID)
 
         local updateResult = insertResult ~= false and Query(string.format(
             "UPDATE custom_coop_players SET credits = credits - %d WHERE steamid64 = %s AND credits >= %d",
-            item.price, SQLString(ply:SteamID64()), item.price
+            price, SQLString(ply:SteamID64()), price
         ), "could not debit purchase")
 
         if insertResult == false or updateResult == false then
@@ -257,10 +419,17 @@ local function PurchaseOrEquip(ply, itemType, itemID)
         end
         sql.Commit()
 
-        state.credits = state.credits - item.price
+        state.credits = state.credits - price
         ownedItems[itemID] = true
     end
 
+    if itemType == "music" then
+        SyncPlayer(ply, state)
+        SendNotice(ply, true, "Purchased " .. item.name .. ". Select it again to play it for everyone.")
+        SendShop(ply)
+        return
+    end
+
     local column = itemType == "model" and "equipped_model" or "equipped_weapon"
     local equipResult = Query(string.format(
         "UPDATE custom_coop_players SET %s = %s WHERE steamid64 = %s",
@@ -357,7 +526,8 @@ hook.Add("PlayerInitialSpawn", "CustomCoopProgressionLoad", function(ply)
     timer.Simple(4, function()
         if not IsValid(ply) then return end
         ply:ChatPrint("[CO-OP] Kill monsters to earn Score and Credits. Your lifetime Score determines your rank.")
-        ply:ChatPrint("[CO-OP] Press F3 or type !shop to spend Credits on permanent models and bonus weapons.")
+        ply:ChatPrint("[CO-OP] Press F3 or type !shop to buy permanent models, bonus weapons, and server music.")
+        ply:ChatPrint("[CO-OP] Bought music plays for everyone. Type !musicmute if you do not want to hear it.")
         ply:ChatPrint("[CO-OP] Dying costs up to " .. Progression.DeathCreditCost .. " Credits, but never reduces Score or rank.")
         ply:ChatPrint("[CO-OP] Type !points for your totals. Hold TAB to compare lifetime scores.")
     end)
@@ -429,6 +599,12 @@ hook.Add("PlayerSay", "CustomCoopProgressionChatCommands", function(ply, text)
         end
         return ""
     end
+
+    if command == "!musicmute" or command == "/musicmute" then
+        net.Start("CustomCoopProgressionToggleMusicMute")
+        net.Send(ply)
+        return ""
+    end
 end)
 
 net.Receive("CustomCoopProgressionRequestShop", function(_, ply)
@@ -445,3 +621,36 @@ net.Receive("CustomCoopProgressionSelectItem", function(_, ply)
 
     PurchaseOrEquip(ply, itemType, itemID)
 end)
+
+net.Receive("CustomCoopProgressionSetPrice", function(_, ply)
+    if not RequestAllowed(ply) then return end
+    if not ply:IsAdmin() then
+        SendNotice(ply, false, "Only server administrators can change shop prices.")
+        return
+    end
+
+    local itemType = net.ReadString()
+    local itemID = net.ReadString()
+    local price = net.ReadUInt(32)
+    if #itemType > 16 or #itemID > 64 then return end
+
+    SetShopPrice(ply, itemType, itemID, price)
+end)
+
+concommand.Add("coop_setprice", function(ply, _, args)
+    if IsValid(ply) and not ply:IsAdmin() then
+        SendNotice(ply, false, "Only server administrators can change shop prices.")
+        return
+    end
+
+    local itemType = string.lower(args[1] or "")
+    local itemID = string.lower(args[2] or "")
+    local price = tonumber(args[3])
+    if not GetCatalogueItem(itemType, itemID) or not price then
+        local usage = "Usage: coop_setprice <model|weapon|music> <item_id> <credits>"
+        if IsValid(ply) then ply:ChatPrint("[CO-OP] " .. usage) else print("[CO-OP] " .. usage) end
+        return
+    end
+
+    SetShopPrice(ply, itemType, itemID, price)
+end)