There are currently two solutions for music notation (computer-generated) on the iPad: Symphony Pro and Notion. Symphony Pro came out in early 2011 and showed a lot of potential (I loved their interface), but the product was buggy and updates were far and few between. A recent visit to the Symphony Pro website simply says, “Symphony Pro 3 coming soon,” and the app itself is not currently available on the App Store. I don't know how long this has been the case, but I'm interested to see what Symphony Pro has to offer!
In other news, Notion posted this update:
We submitted a new update of Notion and Progression iPad apps to Apple a few days ago. We expect Apple will have it approved in the next week or two. This build fixes several bugs that recently appeared with entry, solved items with “select” issues, you can now save/export audio, you will have the first steps in our MIDI implementation with being able to connect a device and use step-time entry, and a ton of other things. Next up…real-time MIDI record/perform, retina graphics, panning, printing from app, more measures per staff options…and much much more. You will see several major product changing updates over the next two months.
That is exciting: more measures per staff (currently 2), exporting audio, and MIDI input.
This is the final frontier on the iPad for music notation…it would be great if Notion can cross that barrier.