1 If you have a MIDI keyboard available and prefer to use it, connect it to Structure Free’s MIDI input, and route it to Structure Free on MIDI channel 1. If there is no MIDI keyboard available, you can play Structure Free by clicking the keyboard on screen, or using MIDI input from the Instrument track in Pro Tools.2 Play some notes on your MIDI keyboard. If all is well so far, you are hearing a sine wave signal from the default Sine Wave Patch at the top of the Patch list.