PROFESSIONAL AND USABLE. This App is incredible. I totally underestimated how good it is. The quality of the backing tracks is truly professional – professional, talented drumming, professional audio, professional arrangements. Coupled with that, I’ve never had an app like this before where it works so well keeping all the tracks in a table and being able to organise them into playlists. You can even play the entire list of tracks with one key press. Incredible. I still can’t get over that there isn’t anything else left to do. It just works great! There are 4 included “factory” tracks that are OK. The Jazz and Blues Sampler app has 23 decent tunes included. These are good to evaluate the app but the real power comes from using it to arrange your own songs/tracks. There’s nothing simpler than this. You won’t believe it. I’ve created some of my own arrangements with 10+ choruses which are how our group plays. I carry it around with me on my iPhone and have it on an old iPad as well, which is good for our jamming. Still works on the old iPad. No problem with speed. Just start with the [Jazz and Blues Sampler] app and then add any tracks you want later. There are 1000s of rhythms to choose from – good ones too. There is nothing else out there anything like this App – it’s nothing like the silly MIDI *dumb* machines. It is real quality, professional, and usable. Recommended.