Songtrix Gold is a music creating software that includes music theory, which can be seen as a set of comprehensive multimedia teaching materials clear and concisely explain what the music is. In the music theory part, it came with more than 118 topics, and illustrated with 350 diagrams and 750 demonstration sounds.
OpenMPT (short for Open ModPlug Tracker) is a popular free and open-source sample-based audio tracker from Germany. It was developed in 1997, based on the classic and original ModPlug Tracker written by Olivier Lapicque. Its design purpose is to make writing music on computer become more interesting, easier and more efficient.