This script always repeatedly picks the same audio after it ends?

local sounds = {"158485547","157026036","158526174"}
local audio = workspace:WaitForChild("Music").Sound
local song = sounds[math.random(1,#sounds)]
local playing = false

audio.SoundId = "rbxassetid://"..song
local currentsong = song
while wait(1) do
	if playing == false then
		playing = true
		audio:Play()
		audio.Ended:Wait()
		song = nil
		song = sounds[math.random(1,#sounds)]
		if song == currentsong then
			song = nil
			song = sounds[math.random(1,#sounds)]
		end
		audio.SoundId = "rbxassetid://"..song
		audio:Play()
		playing = false
	end
end

For example, if the song is the 1st argument of the table, it will stay like that forever. It doesn't pick another random sound?