http://www.irigkeys.io
Watch how easy it is to build a song in GarageBand using only iRig Keys I/O and its included software. From great-sounding drum kits in SampleTank to realistic Syntronik synths to SampleTank's renowned pianos you can lay a great foundation. Then, using the audio interface input on iRig Keys I/O, you have the power to lay down instrument tracks (like a killer guitar part) or vocals to make your song complete.
iRig Keys I/O is a total music production system in a controller. The iRig® Keys I/O series evolves the concept of traditional controllers as the only one available on the market that integrates 25 or 49 full sized keys together with a fully-fledged professional audio interface featuring 24-bit audio up to 96kHz sampling rate, balanced stereo and headphone outputs, plus a combo input jack for line, instrument or mic input (with Phantom power.)