DETUNE Ltd. gave me a copy of iYM2151 for review. This FM workstation is a faithful emulation of the classic Yamaha YM2151 chip, featured in many arcade machines, and big brother to the chip used in the DX7 keyboard. I wish I could do a video review of this one. Partially because it deserves it, but mostly because on these written ones you can just scroll down to the rating and dismiss it. Do so at your own peril; this isn’t an app for everyone, but the people it is for will love it!

iYM2151 has one of the most powerful synthesis engines on any platform, and stands at the pinnacle of what is possible on the original iPad. You have 8 different synth parts, each with their own 4 FM Voice Oscillators and 3 LFOs. Each of the Voiced Oscillators is completed with their own 5-stage amp envelopes, for hugely complex and evolving sounds. Although all of the Voiced Oscillators are limited to Sine waves, as is traditional with classic FM Synthesis, the LFOs can be Saw, Pulse, Triangle or Noise. These can drive pitch, pan or volume.

There are 79 parameters for each synth part! No shit, I added them up. If you have no familiarity with FM Synthesis you will probably manage to shoot your eye out with this thing. I’ve spent a lot of time studying FM and I’m a little over-whelmed by it all. This is an exciting feeling though, and really, with this much to play with the price seems like a bargain.

A particularly novel feature here is the ability to change any one of those 79 parameters at any given step in the sequencer. This goes way beyond some filter sweep programmed in as a MIDI control change. Any step can have an unlimited number of direct parameter changes to specific values, or you can swap out whole presets to change everything at once. This is mind boggling when you get into it.

One of their example songs uses this feature to program several different drum parts all into one synth, by changing the whole synth preset. Nearly every step has a program change from Bass Drum to Hat, to Snare, back to Hat, to Bass Drum, etc… all on top of a traditional note sequence.

Unfortunately these great features are crippled by their slavish attempt to recreate 80s style digital interfaces. You can have a lot of fun experimenting with parameter changes that keep incrementing your tones, but it is a nightmare trying to keep track of it all with this interface. This design decision is maddening. Ask anyone who has ever worked on a Yamaha FM synth and they will tell you that the only thing they hate about it is the interface!

Matters are further frustrated by the manual, which is more of a decoder ring. It will tell you what everything does, but it won’t even make an attempt to explain how you might go about using that. It took me several hours to figure out that to use the Copy feature you need to select and drag the element you’re trying to copy.

After sinking many hours into this app it does become less mysterious, but that actually makes it more irritating. Now I know what it can do, but the cumbersome interface is hiding it all! Sure, it’ll let you change everything from tempo to patches with every pattern, but good luck keeping track of it all when you’re trying to compose a song.

I can understand why they didn’t include MIDI, their own sequencer is more advanced than MIDI could comfortably handle, but MIDI keyboard input would have been nice. Also absent is AudioCopy, or even audio export of any kind. There is the ability to share your songs, but this is puzzlingly locked-in to your GPS location. No shared songs are available for me to explore in the “America/Chicago” area, and there doesn’t appear to be a way to get out of my own local zone.

If you’re a masochistic FM Synth fan, or spend a lot of time on OCRemix, then you will be able to appreciate the power here. Hell, you may even enjoy the archaic interface. Everyone else is likely to just find this a frustratingly disappointing experience.

Here is a demo I put together while exploring the app. It started off as something like Chipstep, but then I got carried away with increasingly incrementing parameter changes in the sequencer. I enjoyed the results, but I won’t be offended - or surprised - if you don’t. A lot of music explores psychedelic themes inspired by mushrooms and LSD, few venture into the more forbidden neurotoxins. Here is my take on PCP House.

iPad Music App Buyer’s Guide Rating: Pass

Recommendation: Easily one of the most powerful apps on iOS, but a terrible interface ruins it.