Why does the boombox stop playing music when uneqipped?

This is an alternative to using the boombox, this is much more efficient. Also, you can use any tool while this is here.

local gui = Instance.new("ScreenGui")
gui.Parent = script.Parent
wait()
local frame = Instance.new("Frame")
frame.Parent = script.Parent.ScreenGui
frame.Position = UDim2.new(1, -400, 1, -35)
frame.Size = UDim2.new(0, 250, 0, 30)
frame.BackgroundTransparency = 0.5
wait()
local text = Instance.new("TextBox")
text.Parent = script.Parent.ScreenGui.Frame
text.Position = UDim2.new(0, 2, 0, 2)
text.Size = UDim2.new(1, -96, 1, -4)
text.BorderSizePixel = 0
text.Text = "Music ID here"
wait()
local play = Instance.new("TextButton")
play.Parent = script.Parent.ScreenGui.Frame
play.Position = UDim2.new(1, -96, 0, 1)
play.Size = UDim2.new(0, 46, 1, -2)
play.BorderSizePixel = 0
play.Text = "Play"
play.BackgroundColor3 = BrickColor.Green().Color
play.Name = "Play"
wait()
local stop = Instance.new("TextButton")
stop.Parent = script.Parent.ScreenGui.Frame
stop.Position = UDim2.new(1, -48, 0, 1)
stop.Size = UDim2.new(0, 46, 1, -2)
stop.BorderSizePixel = 0
stop.Text = "Stop"
stop.BackgroundColor3 = BrickColor.Red().Color
stop.Name = "Stop"
wait()
local sound = Instance.new("Sound")
sound.Parent = script.Parent
sound.Name = "Music"
function play()
    script.Parent.Music.SoundId = "rbxassetid://"..script.Parent.ScreenGui.Frame.TextBox.Text
    script.Parent.Music:Play()
end
script.Parent.ScreenGui.Frame.Play.MouseButton1Click:connect(play)

function stop()
    script.Parent.Music:Stop()
end
script.Parent.ScreenGui.Frame.Stop.MouseButton1Click:connect(stop)

Put that chunk of code in a LocalScript in StarterGui. This will give each player their own personal music player! Hope this helped, if it did then please up-vote this answer.