In Bb 2.0 is a collaborative music and spoken word project conceived by Darren Solomon
There are 16 YouTube videos and you can play them in any order you like one by one or together and they mix well because they are all recorded in B flat. There is a variety of instruments to choose from.
The videos can be played simultaneously -- the soundtracks will work together, and the mix can be adjusted with the individual volume sliders. Its pretty fun!