HexaSawyer 1.0 is a cool, new, music making program that runs on 64-bit Macs running OS X 10.8.5 and above. It uses the built-in DLS MIDI synthesizer provided by the Mac OS to generate and play 4-channel audio.
You can control various aspects of audio produced, such as the instruments being played, the tempo, the scale used, etc. These different aspects can all be altered in real time, during sound playback. Other features include a reverb unit for producing echo effects, automatic variation of the different audio aspects chosen, and storing the selected aspects of audio production for later playback.
HexaSawyer 1.0 is available at the Mac App Store for US$9.99 . For more info go to http://tinyurl.com/qbr2oz8 .