Announcing Sonic Visualiser, an application for viewing and analysing the contents of music audio files. http://www.sonicvisualiser.org/ Sonic Visualiser contains advanced waveform and spectrogram viewers, as well as editors for many sorts of audio annotations. Besides visualisation, it can make and play selections based on the locations of automatically detected features, seamlessly loop playback of single or multiple noncontiguous regions, synthesise annotations for playback, and slow down playback while retaining display synchronisation. Sonic Visualiser also introduces the Vamp plugin API, for plugins that extract descriptive or analytical data from audio. Vamp plugins for onset, pitch and note detection using the Aubio library are available, as well as plugins for tempo tracking, chromagram analysis, constant-Q spectrogram, spectral centroid, power curve and tonal change detection. There is also a comprehensive SDK for use by developers of Vamp plugins and hosts. Sonic Visualiser is Free Software distributed under the GNU General Public License. The 0.9 release is available now in source code form or as binaries for Linux, OS/X, and Windows. For more information and downloads, please see http://www.sonicvisualiser.org/ For more information about Vamp plugins, please see http://www.sonicvisualiser.org/vamp.html See also the SourceForge page for this project at http://www.sourceforge.net/projects/sv1/ Sonic Visualiser was developed at the Centre for Digital Music, Queen Mary, University of London and partially funded by the European Commission through the SIMAC project IST-FP6-507142. Chris