We stumbled upon Adi Musical art shop factory & stock shop on Jalan Suweta. It's about 30 mins walk from the centre of Ubud and is WELL worth the walk. Adi and his wife are the most welcoming, warm and talented couple. You can try out the musical instruments and they are happy to explain how to play each. Prices are extremely reasonable compared to the main markets in Ubud but more than anything, the welcome and kind treatment we received would make me return in a heartbeat.