NumberValue.Changed:Connect() not firing. Why is this happening?

I can't seem to get the NumberValue.Changed:Connect() to fire. It is necessary for this script to work. Any help?

print("Running!")
local mode = script.Parent.Mode
local armBands = script.Parent.ArmBands
local nameGui = script.Parent.NameGui
local music = Instance.new("Sound")
music.Name = "Music"
music.Parent = script.Parent:WaitForChild("HumanoidRootPart")
music.Looped = true

local function changeThemeColor(color)
	print("Changing Theme!")
	armBands.LeftArmBand.Glow.Color = color
	armBands.RightArmBand.Glow.Color = color
	nameGui.NameLabel.TextColor3 = color
end

local function changeName(newName)
	print("Changing Name!")
	nameGui.NameLabel.Text = newName
end

local function changeMusic(Id)
	if music.Playing then
		music:Stop()
	end
	music.SoundId = Id
	music:Play()
end

local function change()
	if mode.Value == 1 then
		changeName("Peace")
		changeThemeColor(Color3.new(0.968627, 0, 1))
		changeMusic("rbxassetid://3221578654")
	end
	if mode.Value == 2 then
		changeName("Purity")
		changeThemeColor(Color3.new(0, 1, 1))
		changeMusic("rbxassetid://2168518839")
	end
end

change()
wait(10)
mode.Value = 2

mode.Changed:Connect(function()
	print("Mode Changed!")
	change()
end)