NNLS Chroma and Chordino

If you'd like to understand chords and harmony better, then this NNLS Chroma library may be just what you want. Version 0.2.1 now has an additional chord note output, and some other improvements.

It's an open source Vamp plugin library for harmony and chord extraction with some features aimed at amateur musicians, and some at music information retrieval researchers.

It contains the Chordino, NNLS Chroma and Tuning plugins described below. Their main features are:

• Chordino: a simple, no frills chord transcription method based on NNLS Chroma features,
• NNLS Chroma: high-quality chroma features for harmony visualisation or further processing,
• Tuning: an estimate of the 'concert pitch' tuning.

If you want to start right away, you can download readily compiled binaries for Windows and Mac OSX (Intel) from http://isophonics.net/nnls-chroma -- Then just use them in a host such as Sonic Visualiser or Audacity, which are also open source.

For the source code check the Repository tab.