Piece: Duo Improvisation for Pandeiro and Laptop
Signal processing, Software: Joseph Malloch
Percussion: Fernando Rocha
Premiere: July 2008

The piece Duo Improvisation for Pandeiro and Laptop was developed by Brazilian percussionist Fernando Rocha and instrument designer Joseph Malloch, specifically for the concert “Electronic Music for Percussion and New Digital Musical Instruments” at Sound Symposium XIV in St. John’s, Newfoundland.  The concert featured pieces for the T-Stick digital musical instrument, an improvisation on the Hyper-Kalimba augmented instrument, and two pieces with “live electronics” (Sergio Freire’s Anamorphoses and Geof Holbrook’s Wooden Stars), so for contrast it was decided to add a piece in which the computer takes an active role as co-performer instead of passively reacting to the human performer.

Starting with the traditional Brazilian pandeiro (a type of frame drum) as source, and using only a microphone as sensor, software was developed to recognise typical musical gestures from idiomatic pandeiro performance (bass and treble hits, jingles and thumb rolls).  A probabilistic model was trained from recordings of Rocha playing, which in turn enabled the software to “improvise” sections of the piece.

The overall structure of the piece was built into the software for performance, but musical cues were used to advance from each section to the next rather than using a foot pedal as is common. The software “listens” for musical cues from the human performer.

Screenshot of the MaxMSP patch used for the piece "Duo improvisation for pandeiro and laptop".