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.
Modstep 1.0.1 update - much better!
While a few bugs remain, I'm now getting pretty good performance from Modstep update 1.0.1 on my iPad 3. I'm not sequencing any external hardware yet (but soon!), for now I'm interested to see if I can construct an IAA-only setup, hopefully to realize my ultimate portable IOS groovebox.
So far I can run about 2-3 IAA synths (Thor, Nave, Sunrizer, Addictive Synth, Phase 84 and Magellan) and the internal synth and sampler, and my CPU hovers around 50-60 percent. It would be very interesting to hear from iPad Pro owners what experience they are having with an IAA only setup. I am guessing at least twice as many synths running simultaneously and even better screen redraw and audio performance. (I am using 512 sample buffer.)
Running anything from Arturia however puts the hurt on the CPU, but I was able to run Sunrizer along with most of the Arturia synths (iProphet, iMini, iSEM). The same goes for Animoog. I'll continue to test out various combinations since the internal synth and sampler are quite capable as well.
Phase 84 and Magellan are good IAA synths to try since they both have 'sticky' presets and always launch with the last one you used. But I am trying to get program msgs to send in a predictable fashion (for the purpose of specific preset selection) but not having much luck doing it with the XY controls, or drawing an envelope. I hope there will be an easier way in the future - such as a program change msg assigned to the clip. The clip can loop, but the program change msg should only be sent once. Come to think of it, there doesnt appear to be a one-shot trigger mode for clips yet, correct?
Modstep is already winning me over. Been waiting for something like this for quite some time! Many thanks to the devs and please keep it up. 
Comments
Anyone been using this with Egoist? i have a feeling that it could make for a good host... But lack of videos on how Modstep works has kept me from trying it for myself. egoist has lots of Midi learn goodness and modstep looks to be automation/modulation goodness.... So I assume ten to the power of goodness awaits me
@AudioGus yes, I've been using Modstep with Egoist with some great results!
I love Egoist on it's own, but using with Modstep... it seems to me that Egoist already has nice step sequence and modulation capabilities on it's own. What would be the motivation to use Modstep with it? For my tastes, I think Modstep is more suited to working with individual synth and FX components, but to each his/her own I guess.
@mkunoff agreed, Egoist is one of my personal faves even standalone but I also like to explore it controlled by Modstep. Caustic and Auria Pro also work well with Modstep.
Agreed and even more so when track/stem record comes in the next update. With Egoist, Caustic and AP, I'll add Stroke Machine, Sunvox, Beathawk (hi Kaikoo).
For Egoist I like using midi to switch patterns and automate settings like slice length, drum pitch, bass parameters etc. While I can do this with a PC DAW well enough it would be great to find an ipad only solution. I am just curious how it is to use the 'midi learn' option in Egoist in conjunction with Modstep.
@AudioGus MIDI learn in Egoist works really well with Modstep - I haven't encountered any issues. Also in Modstep you can quickly copy and create new patterns with different playback speeds, active notes etc., which is perfect for Egoist.
well, I jumped off the fence and got Modstep... But I have an odd bug with setting bpm. The bpm button is invisible until i tap it and the ui is totaly buggy... Here is a video...
ahhh, seems to work when Ableton Link is enabled....
@AudioGus Please keep telling me the water's lovely and you've never been happier. Or not. Or why. This fence is getting very pointy.
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Yes but it's not right. It doesn't lock in correctly.
@AudioGus, they knew the tempo issue!
I think it's very good now and worth getting at this price still with the few issues that remain. A few updates and things will probably get much better
Is there a trick to getting the speed controls working? i set them to 2x or 1\4 but nothing changes...
When you touch that 2x, your next step should touch the Step Sequencer pad (1-16th pads) to make it showing the 2x on the conner. Otherwise, it does not know which pad to send to.
Ahhh! thank you! I assumed it would change the current one but that would mess things up. something tells me a lot of this may be like Ableton which I have not used.
surely they won't raise the price until the insects have left the building?
Anyone got this working to sequence VST via studiomux-.audiomux yet on Windows? If so how's the midi set up to feed data to the VST synth?
I must say, this is pretty amazing for sequencing Egoist...
Because your fingers are ultimate randomizer. So it all depends on ultimate transistors from brain. He he, just joking on you, never mind!
hehe, its all good captain
Alrighty, so after a day of playing with it and getting so completely addicted I must say that the workflow is awesome and fun. I can't wait for the recording features to get in. As for the initial bugs I encountered they were pretty much the only ones I found (tapping blank CC slot insta-crash and the weird bpm ui). The random crashing went way down too over time, as strangely enough seems to happen with some apps. Anyway, I can't wait for the multi-IAA recording feature to get in. It will be a great commute killer and I also can't wait to see what happens running Modstep on two ipads while linked. 8)
@AudioGus Can't argue with that Skipper and anything that transcends the commute is worth the pennies, no doubt. I think I will be climbing down, but have my hands so full right now with app busyness that I will probably wait for the next version.... thanks for your take. Much appreciated.
Keep promise and abide by the rule, two weeks without app purchase!
Can only play blues song!
Your lovely the other half will appreciate I helping you quitting appaholic!
I can confirm the tempo issue - it works only when Link is enabled.
Also, using Arturia synths in Modstep seems to be a no-go with my iPad 3. Some patches are ok, but otherwise too much bandwidth is taken up by iProphet, and then Modstep's own internal instruments latency/response suffers. Taking Arturia out of the equation seems to be needed for my 3rd gen iPad. I could try some experiments with 1024 sample buffer, but I really dont want to go above 512.
A combination of any of these 3 (Sunrizer [and XS], Magellan, Phase 84, Thor and Nave) plus the internal Modstep instruments seems to be quite stable so far. Admittedly, I need to do some more testing with Nave and Thor, as they are are more likely to be CPU hogs on more complex patches.
Thoughts about improvements...
-The sampler in Modstep is pretty nice already as a basic drum machine, but it would be nice to have some overdrive on the filter or a separate basic distortion.
-The synth is also understandably basic. I realize the whole program is a "modulation onster" by why only offer LFO and envelope for volume only? More LFOs and envelopes for filters would be great!
-One shot trigger mode for clips.
-Program change messages assigned to clips for preset selection via midi. They should only be sent on initial clip launch and should not loop.
-Midi feedback indicator (maybe flash the midi panic symbol?)
-Classic piano keys UI for live midi recording note input (or did I miss this somehow?) I only see one in the chord editor.
Cheers to the devs! Really diggin the Modstep paradigm so far.
Master @Kaikoo
Is it possible to sync playback between AuriaPro and Modstep?
Sorry, my disciple!
The answer is No at this moment.
You can only manually start the Modstep playhead and record Modstep midi to Auria (ie. Modstep play Lyra or Twin2 ).
Modstep itself has no IAA audio output and no IAA midi output to DAW, that means no audio insert slot inside Auria also no midi instrument insert slot inside Auria.
Maybe next update you can have Auria driving Modstep playhead.
I played around to answer your question, hope you are satisfied!
Thank you very much sir, I really apreciate the investagation! Maybe Auria Pro with Link at some point...
Please, extensive manual or tutorials!