The Echo Nest is a music technology company founded by two MIT Media Lab PhDs. The Echo Nest’s proprietary music analyzer API automatically analyzes audio (e.g., aif, wav, mp3, m4a), and generates an XML file describing the musical and structural content of the music. Computation takes about 1/50th of the duration of the track and the text output is about 1/20th of the size of its corresponding mp3.