Exporting to midi file in iOS

[David Blake]

Hi,

I frequently get requests from users to incorporate export to midi as part of my iOS app. I certainly know this is possible as many popular music apps offer this feature. I was just wondering if anyone knows where the best place to get started with this would be? Looks to me like the MusicSequence data type in the AudioToolbox framework might be what I'm looking for, although didn't really find many examples of people implementing this on iOS. Other people appear to have rolled their own solutions, but maybe that is out dated and something now native in iOS does the job. 

Anyone with any experience in this that could point me in a direction I would be most grateful for.

Cheers!

David