From Music Hack Day
MashTV is a personal streaming video mashup playlist, created using the Echonest API & Youtube videos.
Hector Parra, Jordi Hidalgo & Oscar Casanovas (3 SMC Master Students at the MTG, UPF, Barcelona) Twitter: @oscar_miaau
 About the hack:
The hack uses a song seed (artist name & song name) to find similar tracks (Same Key, Mode(Major/Minor) and BPM) by similar artists. This is done with the Echonest API. Then we use the Echonest remix API to detect the sections of the selected songs and create a looong video mashup file, which should be then streamed online to the user (not implemented yet). We have successfully generated mashups with more than 5 different songs in one video.