The other day I was looking for any information on anything where people created digital musical instruments with Arduino boards. To my luck a guy made an open source project (much like mine will be) that turns the Due board into a fully functional step sequencer and DDS (direct digital synthesis) synthesizer. The project is called Goovuino and its last blog post was well over a year ago. Using my own hardware designs I'm going to be able to use this library to construct the step sequencer.
The interesting part of this project was learning how DDS really works. I had a rough idea that to generate a waveform using sample data and iterating an array. The biggest thing I picked up while learning about it is how to do fixed point integer arithmetic. This blog post has helped explain in depth on what is expected of the hardware when I plan on implemented DDS with the Due.