hi all i am trying to make a musical app for iphone. the app is simple. there is a couple of musical note sample (caf) files. when user taps the predefined positions on uiview(like strings). app plays note sample and add a string value to a nsmutablearray about note. played note lists displays in a table. now i want to add a shake and play mode to app. when user shake iphone, recorded notes start to play from first record to last record and loop again. also if user shake iphone harder notes will plays faster. how can i do that. any idea? thanks