Evan Parker has been playing this kind of music for so long now that he doesn't so much use extended techniques as draw on a deeply internalised lexicon of unconventional approaches to the saxophone, most of which he pretty much invented. It's a language that has been available for subsequent generations of improvising saxophonists to learn and develop – players such as Seymour Wright, who has known Parker since childhood and literally grew up listening to his music. Little surprise, then, that the endlessly inventive musical conversations on this disc feature two voices that echo, entwine, interrogate but largely agree. Parker mutters and growls on tenor, and spirals skyward on soprano, while Wright see-saws on alto, interjecting with brittle harmonics and abrupt stops. Yet, for all its experimental intent, it's fascinating to hear how the vocabulary remains grounded in jazz, with low, trombone-like growls and great, yearning, upward swoops like Sidney Bechet's clarinet about to launch into ‘Summertime’. Let's just call it music.