What at first sight looks like the title of a study book in mathematics, turns out to be something far less sinister. It's a collaboration between a pair of Aussie bands sitting on different sides of the musical fence, yet looking to explore common ground. The band that Jazzwise readers might be more familiar with is piano trio Trichotomy, having made three very impressive albums to date on the UK's Naim label. Now close to 15 years together, Trichotomy is informed by the post-millennium giants of the format from EST and The Necks through to Brad Mehldau, yet they still manage to create their own unique space in a crowded format. While the previous album Fact Finding Mission for the first time involved guest contributions, Healthy is a full-on joint collaboration with new music ensemble Topology. Compositions are split between both sets of band members with an instrumental version of Steve Reich's ‘Clapping Music’ the only exception. The latter though points to a general emphasis on 20th-century minimalism with originals made up of oddmetered metronomic pulses and ‘phasing’, perhaps closest in feel to Michael Nyman's earlier chamber works and film scores for Peter Greenaway. References to the music of Pat Metheny, Frank Zappa and Astor Piazzolla emerge as well but as a subtle ingredient and there's some resemblance to recent work by former EST drummer Magnus Öström's Band. But the paradox is that for such a rhythm-orientated music, this is a far less exciting and free-flowing set than when Topology and Trichotomy perform as separate entities. In other words the whole is not greater than the sum of its parts. Perhaps Healthy would have benefitted from being a bit unhealthier.