Invenio Ergo documents two sets that SUM – drummer Eddie Prévost, guitarist Ross Lambert, and alto saxophonist Seymour Wright – performed at London's Café Oto in February 2009. Lambert and Wright are long-time participants in the weekly workshop that Prévost has run over the last decade, and based on that and GAMUT, his duo with Wright from last year, listeners may come to this one expecting rigorous timbral abstractions. And that's how things seem to start out, with Wright's alto pecking across the drummer's restive patterns. Then Lambert's jazz inflections comes in, Prévost kicks in to a free shuffle, Wright starts introducing melodic kernels and slowly, an oblique take on the language of jazz begins to emerge.
Eddie Prévost is adamant about not buying in to non-idiomatic dogma when approaching his music, but there is an apparent bifurcation between his jazz-based work (the trio with Tom Chant and John Edwards, or the Free Jazz Quartet) and, to coin a term he used in his notes to GAMUT, his "experimental improvisation practice" (AMM, his solo work on rototoms and tam tam). SUM grapples with the intersection of these strategies head-on. Prévost's roots certainly go back to bebop, Lambert's resonant tone and clear attack align to jazz voicings, and Wright has happily acknowledged an allegiance to the vocabulary of jazz (though, based on what I've heard, you certainly wouldn't think of him as a strong jazz stylist). But we're not talking about Braxton's ongoing forays in to the jazz repertoire or Rova's reorchestrations of Coltrane's Ascension; the strategy here is about addressing not the forms of post bop and free jazz, but the contextualization of jazz language, a collective take on the patterns and rules of canonical playing.
Melodic threads are morphed through refractions of free bop phrasing, a connection driven home on "Invenio" when Wright floats in "Stella by Starlight" and "Giant Steps." He toys with melodic fragments, twisting and exploding them as he moves freely between gruff edginess and textural deconstruction, while Lambert cuts across his trajectory with warm chords and splayed lines and Prévost feints and weaves around both of them with a dazzling sense of abstracted swing. "Ergo," which takes up the entire second CD, is a study in the collective deconstruction of Oscar Pettiford's "Tricotism." Over the course of 40 minutes, the theme is introduced, teased apart, dissolved, and reconstituted with gripping collective focus.

It's tempting to place the music of SUM in the same context as The Free Jazz Quartet, another ensemble Eddie Prévost has played in. Both groups reference jazz, but the FJQ is motivated by a different aesthetic and looks at the jazz tradition through an entirely different lens. Trombonist Paul Rutherford, reed player Harrison Smith, and cellist Tony Moore first got together in 1988 to engage in demonstratively conversational, polyphonic improvisations driven by Prévost's gregarious drumming. Their only previous release, Premonitions, came out on Matchless over ten years ago. Rutherford's jazz background is well-known, but Harrison Smith's is no less important. He's played with musicians like Mike Osbourne, Kenny Wheeler, Chris McGregor, and as part of the South African inspired group District Six. Moore's interests range beyond the strictly musical, and have included collaborations with dancers and visual artists in improvised settings.
The eight pieces on Memories for the Future, an animated set recorded live in Bristol in 1992, ride along on a relaxed sense of free swing. The trombonist provides his inimitable wry phrasing and blues bluster tinged with acrobatic smears, while Smith is more considered, less boisterous, and brings an open melodicism to the proceedings. The way that the two work off each other is a study in contrast and balance. Moore makes the most of the entire range of his cello, moving effortlessly between propulsive momentum and linear counterpoint, bringing out the complex rhythmic underpinning of Prévost's hyperactive playing. It's a great snapshot of the four in full flight and a vital reminder of what a great player Paul Rutherford was in a jazz-based setting.
— Michael Rosenstein PARIS Transatlantic Magazine February 2010