Carillon My Wayward Son

YouTube via peahix. Anyone know what the interface on top does?
"This is a preview of a piece I wrote for the UCSD Geisel Library Carillon. You can hear the official performance on Jan. 23rd, 2009 at 12 noon. Just be somewhere in the vicinity of the library. You won't be able to actually SEE anything being performed, as the carillon is housed in a small cement room atop the library in a restricted area. But this video will give you an idea of what the carillon looks like. The "bell" are amplified metal rods that play over a loudspeaker system on the roof of the library. Included in this video are some shots of the library that I took after practicing the piece, in case you've never seen this amazing building. Thanks to Scott Paulson for commissioning this piece! For more info, see http://blog.ucsd.edu/artslib/2009/01/..."