So, I think I need a synth chip.
But, I don't have any idea how good a General Midi sound would be at simulating a chime if the chimes are not a normal chromatic scale.
Featuring Yamaha's high quality AWM2 tone generation technology, the MU10 has 676 Normal Voices and 21 Drum Voices (percussion sets), with full General MIDI compatibility -- including Yamaha's new XG-MIDI. It provides 16-Part multi-timbral capacity and full 32-note polyphony for playback of even the most sophisticated song data.
I imagine it should be possible to craft sounds on the teensy graphical editor in a similar way that he does with the graphical editor of puredata.