B-Keeper is a software system that synchronises Ableton Live to the beat of a drummer.
Currently, many bands in the studio and at gigs use click tracks consisting of metronome-like clicks fed to the drummer via earphones. They are needed because bands commonly use sequencers and synthesized sounds in their music and they need to stay in time with these parts. But by providing a rhythmic straitjacket, a click track gives the drummer no freedom at all to vary the rhythm and means they cannot speed up or slow down, for example in response to the mood of a crowd at a gig or because they ‘feel’ the music differently from a previous performance.
B-Keeper gives drummers the freedom to speed up or slow down the pace of any pre-programmed music, the material following their lead. The drums are linked to the software via microphones, with both the kick and snare drum miked up. The drummer can add groove into their live performance, being able to speed up or slow down by around 5% and still keep pre-programmed parts of the music in line with the beat. It means that drummers no longer have to keep time with a click track and the set beat of pre-recorded tracks that are used during many live performances and studio sessions.
It is available as a MaxForLive plugin and also as a standalone patch in MaxMSP. It was developed by Andrew Robertson at Centre for Digital Music, Queen Mary, University of London. He is a Royal Academy of Engineering/ EPSRC Research Fellow at the university. B-Keeper has now been successfully trialled by Higamos Hogamos, London-based psychedelic rock band.
The user requires two Java externals, available from the site (to be placed in Max5->cycling74->java->classes), and the onset detector object Bonk~, that must be downloaded independently (and placed in Max5->cycling74->max-externals). Links are on the website. A visualiser application, made in openFrameworks, is also available that shows what the algorithm is doing.
Videos are on http://www.youtube.com/bkeepersystem
How did this project use Max?
B-Keeper has been programmed as a Java external with a MaxMSP interface. It is available as a Max For Live plugin. By placing it across a stereo track with kick and snare drum microphone input, Live will automatically synchronise to the drums.