Perhaps the rumours about New York free jazz pianist Matthew Shipp trading in his upright for a sampler and synthesizer aren't so far out after all. Masses is credited to London breakbeat team Spring Heel Jack, but in truth it's a Shipp-organized project featuring the best of the improvised jazz world messing with beats. The fusion between electronic sounds and full-throttle jazz is more sublime than expected. Shipp, bassist William Parker, horn players Evan Parker, Roy Campbell, Daniel Carter and Tim Berne and percussionist Guillermo E. Brown kick up their usual moody racket, which is then plied, steamrolled and rewired by Spring Heel Jack. The electronic crew don't add beats to the mix so much as an unusual energy. It's not jazz and it's not electronic music, but something almost in the middle.