Revered in the jazz world but less broadly known outside it, the Canadian-born, London-based Kenny Wheeler had a uniquely warm, soaring sound on trumpet and flugelhorn, and his compositions evoked a sense of melancholy and deep lyricism like no one else. Following his earliest efforts as a leader, he began a fruitful tenure on the ECM label in 1976 with the classic Gnu High. The quartet lineup was simply extraordinary: Pianist Keith Jarrett, in a rare sideman appearance, found a natural rapport with bassist Dave Holland and drummer Jack DeJohnette. The three of them had worked together in the recent past with a far more famous trumpeter, Miles Davis, who was surging headlong into his late-career electric period. (Jarrett and DeJohnette had bonded even earlier in Charles Lloyd’s epochal Forest Flower quartet.) Gnu High is wholly acoustic, and Wheeler’s sound world of arcing melodic leaps, expansive harmony, and rippling, elastic swing—what he once self-effacingly described as “soppy romantic melodies mixed with a bit of chaos”—is distant from Miles Davis’ abstract jazz-funk of the period, yet handled just as transcendentally by these illustrious bandmates. (Davis was beginning his mid- to late-’70s hiatus when Gnu High came out.) There are just three cuts. The full album side “Heyoke” ebbs and flows and transforms over an eventful 22 minutes, ending with as striking and finely wrought a compositional moment as Wheeler ever achieved on record. “Smatter,” a concise, doggedly swinging tune with a pithy rhythmic hook at the end of the form, became a modern jazz standard of sorts, widely played by Wheeler’s admirers and stylistic heirs. Finally, “Gnu Suite” begins with a dramatic trumpet-piano duet and winds through dazzling unaccompanied bass and drum solos, all the while capturing the essence of Wheeler’s harmonic approach and mood. The material is elegant and structured, but the improvisation can grow to become white-hot: Jarrett in particular plays with a fire and sublimity that makes Gnu High an essential part of his discography as much as Wheeler’s.