This is a preview of an upcoming polychord release. In this video, we're using polychord (BETA) as a MIDI keyboard for nLog Pro (BETA) -- all on one iPad, all without any cables.
App makers are starting to work together to make all of your iOS music apps play nicely with each other through virtual MIDI.
This is still experimental, and it will be a little while until app makers optimize their apps for multitasking, and enable virtual MIDI. It's very exciting and clearly the future of iOS music making.
If you are a developer, get involved with the open music app group: groups.google.com/group/open-music-app-collaboration