The Build Your Music robotic xylophone is designed around the Trophy 25-note (2-octave) bell set. I chose this one because it met my criteria of being reasonbly priced (under $100), and yet had a good enough sound that I could feel satisfied when listening to it.
The Trophy Bell Set is available in multiple configurations:
- 25-note Chromatic G-to-G (Model Tr9012)
- 25-note Chromatic C-to-C
- 25-note Chromatic A-to-A (Model Tr9001)
- 17-note Chromatic C-to-E
- 8-note Diatonic C-to-C
Any of these Trophy Bell Sets can be used. I prefer using one of the 2-octave 25-note models, because with both the white and black notes, it is possible to play songs with both the melody and harmony. Also, 2 octaves is a wide enough range that most songs are recognizable when played. The instructions on this web-site are shown using the G-to-G Model Tr9012, which is also pictured below. As of this writing, this instrument can be purchased from guitarcenter.com for $60.