Audiobus: Use your music apps together.
What is Audiobus? — Audiobus is an award-winning music app for iPhone and iPad which lets you use your other music apps together. Chain effects on your favourite synth, run the output of apps or Audio Units into an app like GarageBand or Loopy, or select a different audio interface output for each app. Route MIDI between apps — drive a synth from a MIDI sequencer, or add an arpeggiator to your MIDI keyboard — or sync with your external MIDI gear. And control your entire setup from a MIDI controller.Download on the App Store
Audiobus is the app that makes the rest of your setup better.
A request to developers re: note naming
If you're going to have notes named (e.g. C3, B4, etc.), please, please, please have a method for allowing the user to define what Middle C is!
For anyone unaware, there is no standard for note naming. The MIDI Manufacturers Association only specifies note numbers. Here middle C is clear, it's note 60.
But when it comes to names, nothing was ever defined, so different manufacturers came up with different naming conventions.
Yamaha call middle C (note 60) C3. This comes from their originally using 61 note keyboards where middle C was the third C on the keyboard. It gives the full 128 note MIDI range of C-2 to G8. A bit odd, but, it's probably the most common naming convention; it’s what most apps seem to use (modstep, Garageband, Senode, BeatMaker 3, Infinite Looper, Audio Damage apps etc.) As well as Ableton, Arturia, Novation, DSI, etc.
Roland used C4 for middle C, so the full MIDI range is C-1 to G9. There are several apps that use this too (AUM, Xynthesizr, MIDIFlow), but it is probably slightly less common than C3 in the software world (but with Roland and Korg, just as common in hardware?).
Some people propose C5 as this relates to the MIDI Spec / programmer method of counting from 0 (so a full range of C0 - G10), but I don’t think I’ve ever seen it used in commercial products (note: you might think apeMatrix is one such app as the keyboard starts at C0, but this note is actually the 13th note; you don't have access to the lowest octave).
And then there's middle C as C6. This comes from C1 to G11, using common counting starting from 1, not 0. There is, actually, one app that uses this: Fugue Machine.
All of this means that trying to get stuff to work together can be very confusing.
Developers, please have a method of switching between what middle C is named! C3 and C4 are, by far, the most common, so all that is really needed. However, ideally, there would be a setting for note numbers as well; as numbers are probably the most useful when setting up triggers.