Good-sounds.org is a platform for sharing and evaluating instrumental samples developed and maintained by the MTG-UPF and KORG, currently supporting single notes played by 5 instruments: flute, clarinet, trumpet, cello and violin. Musicians can register and upload their sounds, which are then analyzed using the Artistry technology. Using Artistry the system measures how close the sounds are to the ones that the community has identified as reference sounds. The community of musicians active in the site establishes what is a “good-sound” by voting on the uploaded sounds. From these votes the system learns how to evaluate sounds and how to give a score to them. These scores evolve as the community gives more feedback and the system learns from it.The goal of the good-sounds.org initiative is to extend the platform, supporting more instruments and types of playing exercises, making it of use to all music students. But for this initiative to become really useful it requires the participation of musicians. Their sounds and feedback is what will make the system become a good tool for musicians, helping them to learn more about their playing.