With this lasercutter, accessable through UT Architecture Dept I fiddled with laser power settings, speed settings, shapes to cut or etch, materials to cut or etch eventually discovering that the most crisp sounds come from, of course, full power + full speed, and on smooth materials [i used 1/2" MDF board] so variations in sound come only from changes in whether it is etching a horizontal line or vertical line or a curve.

[the sounds you hear were created from the etching of the pattern in the background of each block]