Hi everyone,
mekidsmom asked me to post a little bit about Chordino and Sonic Visualiser. It's a software that Chris Cannam, a colleague of mine at Queen Mary University of London, has developed.
The Sonic Visualiser program was designed so that researchers who look into the automatic analysis of musical audio (e.g. myself) have a tool to see how well they are doing, and for musicologists and all others to be able to look at different aspects of an audio recording (spectrum, beats, ...), make annotations and play back annotations. The software is stable, free, open source, and you can download compiled binaries from the Sonic Visualier website (http://www.sonicvisualiser.org/). But it is NOT an audio editor 
One of the cool things of Sonic Visualiser is that it can connect to so called "Vamp" audio analysis plugins. There's a growing arsenal of those to be found on the http://www.vamp-plugins.org/ website: tempo estimators, beat-trackers, segmenters, onset detectors, and many more weird or not so weird ones. By the way, the audio editor Audacity is also a "Vamp host", i.e. it can also make use of these plugins.
---> What makes Sonic Visualiser (and any Vamp host) relevant to this forum is the addition of the new Vamp plugin for chord extraction: "Chordino" (http://www.isophonics.net/nnls-chroma). It works like this: you load a music file into Sonic Visualiser and run the Chordino plugin (if you have installed it ) and you get a decent chord transcription in many cases. No automatic chord transcription is perfect, but Chorino certainly gives you a good idea of the chords for many songs. I worked on this for my PhD, and when Chris asked me if I could release it as a Vamp plugin, I said yes. So that's what we did last week. All of this is sponsored by the UK government (i.e. Chris and I get our money from researching stuff, and not from selling software), so it's all free to download.
So, to summarise:
- you can download the Chordino plugin for chord transcription from http://www.isophonics.net/nnls-chroma
- you can download Sonic Visualiser from http://www.sonicvisualiser.org/ and also find lots more information.
- you can download lots more Vamp plugins from http://www.vamp-plugins.org/
- they are all absolutely free.
- installation guidelines can be found in a video: http://www.youtube.com/watch?v=ojtkaoV0N48&hd=1
- a Chordino example: http://www.youtube.com/watch?v=bditeyrH56M&hd=1
Reviews of SV ... I don't know, it's had a pretty academic following so far, but it's easy to use, so even musicology researchers like it. Maybe the best review is that it is being used by lots of different people: http://scholar.google.co.uk/scholar?hl=en&q="sonic+visualiser"
If you prefer you can use Chordino with Audacity 1.3.12 (not with 1.2.x) and there are lots of reviews of Audacity, I believe, and loads of videos: http://www.youtube.com/results?search_q … y&aq=f
All the best!
Matthias
