Intonation Software

 This section describes Helm, the software suite that was developed to realize pieces using dynamic intonation. (As the astute reader may be able to guess, it is named after the great acoustician and tuning theorist, Hermann Helmholtz.) Helm operates on score files written in a simple Score Description Language (SDL) that gives pitch, duration, and intonation information. It can create Standard MIDI Files (SMF) [5] from these scores, and then the SMF can be played back to realize the piece. Helm can also follow along in the score as it ``listens'' to the MIDI data from a performer's keyboard, transmitting a retuned version of this MIDI data to a MIDI synthesizer in real-time.

Below, we will first discuss two topics fundamental to both the SMF and score following modes of operation. These topics are the score representation used by Helm (SDL) and the technique used to tune MIDI synthesizers. Then we will proceed to discuss the SMF and score following modes of operation.