Best API for iOS Music Notation and Playback

I'm constructing an application that allows you to compose and play back your compositions for iOS. I looked into CoreMIDI (new to 4.2), but I'm not looking to interface with any keyboards or other MIDI hardware and think there may be a simpler way. Does anyone else h开发者_JAVA技巧ave any suggestions on the best API to use for this type of task?

I'm also looking for something similar. I found this app (PocketScore), mentioned in this thread: Muscial notation on the iPhone. Any suggestions for example code?. However I couldn't find an API / Framework.

Is something like PocketScore that you are looking for? That is, "visual representation of music"?