The app comes with only 3 styles of backup- medium swing, Latin/bossa, and pop rock. The additional styles sets are extra $$ but worth it. Songbooks like the jazz 1300 are a free download from the site (all the realbook volumes & then some ). All in all the sounds are on par w/ band in a box though not as tweakable. the fact that you can chart ideas on your phone / pad makes it my go to. I wish I had this when I was in college, it would have saved me sooooo much time practicing.