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 StoreAudiobus is the app that makes the rest of your setup better.
Atom 2 orchestrated by Senode (iPad only)
Here is an AUM session that I put together over the last week or so which demonstrates the use of Senode (iPad only) as an Atom 2 orchestrator:
https://github.com/MisplacedDevelopment/AtomArranger
(Uploaded to GitHub to save Michael some bandwidth 
)
See the PDF file linked from the GitHub page for more detail.
I used the project as an opportunity to learn a bit more about the MIDI controller side of Loopy Pro and so there is also a little menu thing in there designed in Loopy Pro.
The other 'interesting' part is some StreamByter code which injects record MIDI messages into Atom to try and simulate continuous recording when switching between clips.
It has not been heavily tested and there may be some gremlins lurking inside the recording functionality.
Any questions/suggestions etc, add them here. I am going back to making music now that I have got this out of my system so I can't guarantee that I'll do any more work on this in the near future but feel free to either suggest changes or make them yourself and contribute back.
I hope this AUM session, or some component part of it, is useful to someone.
Comments
Very impressive!
Thanks @tk32! I did think of how useful your great Atom 2 docs were when I was considering whether or not to bother writing some documentation for this
Despite saying I was not going to add anything else in the near future, espiegel123 helped me understand how to get Loopy Pro widgets to react to incoming MIDI so I implemented a "REC status" view in v1.1 which lets you see which Atom instances are set to record without needing to open StreamByter (the 8 red oblongs in the top right of the image below):
After watching all of those great videos today on using Scaler 2, the first thing I thought after using it properly for the first time was “hey, this might also work as a decent Atom arranger”. I may well be broken.
It does actually seem to work to drive Atom in the same way I was using Senode. You just need to use the individual trigger MIDI notes (0, 2, 4, 6 etc) to trigger each Atom instance from the sequencer/pad menu and make sure the MIDI channel in Scaler is set to the target track number. One advantage over Senode is that you can easily repeat parts and also add in rests where necessary. I expect you will also be able to define triggers longer than 16 bars, which was the Senode limit. It is a shame you can’t manually name each pad as that would have made it easier to see which pads correspond to the different Pxx Atom instances.
I’ll take a closer look tomorrow and update the session if it is worth pursuing further.
I have added two new AUM sessions that include a set of wired-up Scaler instances that will by default run through each Atom instance in order. You can long press the Txx button at the top left of the Track Window to bring up the Scaler instance for that track.
The main downside to Scaler is that I don’t think you can have it start at an arbitrary point in a pattern so the whole song starts again if you restart the transport. With Senode you can set the song to start at any node, meaning that you don’t have to sit through N bars to get to the part you are interested in. Perhaps better for final arrangement purposes…