Me and my colleague from the university (Margus Niitsoo, PhD) have been working on sound recognition lately. I recorded hundreds of samples on different guitars this summer to form the basis for machine learning. Now our virtual professor can distinguish between different pitches and chords pretty accurately. Rhythm, timing and tempo recognition is under development. As a result of our work this week we launched our first interactive guitar game. It is called the ChordInvaders. You can try it out at: www.strumprofessor.com I used the game to practice chords on the renaissance lute and worked very well 🙂