I absolutely love seeing the musical tastes of my kids emerge as they learn how to build playlists and search for songs they've heard once or twice and liked.
My 11 year old is just now getting into ‘her own’ music, and her playlist is (predictably) all over the place.
I think age 11 is where the wildest variety shows up, because they just like what they like and haven't yet been pressured to run it through societal filters.
My kids aren't having friends or TV shape (shame?) their musical tastes as much as if they were in school...and they also have influence from me, my husband, and their teen siblings too.