Yeah you can put music in it.  I do.  But you can also put other types of paperwork in it.  Whatever.  It has two diagonally-oriented elastic straps to keep it shut so your papers don't go all over the floor.  I LOVE those.  They work great.  It is black but not shiny like typical vinyl, so it's good for concert use.  It's thick and sturdy and not likely to fall apart as easily as some of the folders I've owned.