Bol Processor BP2
QuickStart and reference manual


This document does NOT cover any of the changes since BP 2.9.3, such as new or changed functionality in the MacOS X version. For help with these changes, please try the new, in progress, Bol Processor Documentation Project, or refer to BP2's online help and the other information that came with the application.

This document also does NOT yet contain information about important musical features added in the late nineties such as _tempo, _retro, _keymap, _transpose, etc., all of which are documented on-line in BP2 and introduced in <>.

This is the first version of the full documentation converted to hypertext. A few problems remain to be solved with the automatic conversion. The original document is available in MS-Word format. (Click here to download it!)

In the early 1980s, ethnomusicologist Jim Kippen and I developed a computer system called the Bol Processor (i.e. "BP") to help us examine improvisatory methods used by North Indian tabla drummers (Kippen 1987, 1988, Kippen & Bel 1989b, 1989c). Designed for the portable Apple IIc, the rule-based BP1 was able to analyse musical input (in the form of tabla bols, or onomatopoeic syllables) as well as generate new improvisations that musicians could assess. Details of the philosophy behind BP1 and its modus operandi can be found in our paper: "Modelling music with grammars: formal language representation in the Bol Processor" (Kippen & Bel 1992).

The Bol Processor attracted interest from scholars and musicians alike. It was felt that the formal model embedded in it could be expanded to encompass more general musical structures, and in this form could be of some benefit as a tool for music composition. We therefore decided to implement an alternative version of the Bol Processor on the Apple® Macintosh. An enhanced version of the algorithmic part of the Bol Processor, namely "BP2", was written in the C language. A sound-object editor allowed it to interact with MIDI devices.

BP2 deals with incomplete representations of polyphonic/polyrhythmic musical structures. It uses a very efficient algorithm for the synchronisation of sound-objects.

With version 2.5 important features have been implemented, notably an accurate control of all MIDI parameters and automation of tasks with scripts. Version 2.6 introduced client-server technology. The present version is interfaced with Csound, deals with MIDI files, and works under Opcode OMS.

BP2 won the Bourges 1997 international award (ex aequo with Piché & Burton's "Cecilia") in the category of computer-aided composition and realization software. It is currently jointly developed by Bernard Bel and Srikumar Karaikudi Subramanian.

BP2 may be downloaded from its home web site: <>.