[ROBLOX] Help with making a music player with youtube-like time position bar?

I'm creating a gui, I want to be able to match the position of this bar, ( Like a sliding bar, Like in youtube) with the position of the song.

So, The length of bar is 240, The sliding bit can be anywhere from 0 to 240, But the song can have any length, Is there anyway I can get the bit to move across with the song? and reach the end at the same time? Or a very similar time? I can't provide much code as it wouldn't be really helpful, Although If you do want it I can provide it.