hi, I updated my macbook pro last night to yosemite and now some of my music doesn't play in itunes or even in preview. In the same albums there are some that play and some that don't even open on itunes and when i open them in preview it says that they have 25ish minutes. I thought i might have saved the music to my hard drive incorrectly but i tried them now in VLC and they all play. Anyone has any idea how to solve this?