George Duke had the kind of career nobody gets to have anymore. His discography spans highly complex progressive rock, jazz fusion, R&B and funk, Brazilian music, and combinations of all of the aforementioned. He had jazz cred and chart hits, and was a vital and well-regarded sideman to Frank Zappa during the rock jester’s most creatively incendiary period.

Duke first achieved recognition alongside Jean-Luc Ponty; his trio backed the electric violinist on a co-billed 1969 album, and while performing at a Bay Area nightclub, the group was seen by Zappa and Cannonball Adderley (separately, one assumes), both of whom Duke would go on to work with.

Duke played piano on 1970’s King Kong: Jean-Luc Ponty Plays the Music of Frank Zappa, which featured tenor saxophonist Ian Underwood and drummer Art Tripp of Zappa’s band, the Mothers, and FZ himself guesting on one track. And within the year, Duke was recruited into Zappa’s company of players, where he stayed from’69 to’70, leaving to back Adderley in ’71 and ’72, and then returning from ’73 to ’75. He can be heard on Chunga’s Revenge, 200 Motels, Waka/Jawaka, The Grand Wazoo, Apostrophe, Over-Nite Sensation, One Size Fits All, and the live Roxy & Elsewhere, as well as Bongo Fury, Zappa’s 1975 collaboration with Captain Beefheart. He also played on much of the material that was originally slated for the four-LP set Läther, and which wound up on Sleep Dirt, Studio Tan and Orchestral Favorites.

Cannonball Adderley’s recently reissued double live album, The Black Messiah, is one of three documents of Duke’s tenure in the saxophonist’s band (the others are 1972’s The Happy People and 1976’s Music, You All, the latter of which was recorded during the same engagement at L.A.’s Troubadour that yielded Messiah). The piece “The Black Messiah” itself, which opens the album of the same name and runs over 16 minutes, is a Duke composition. Throughout the show, he shifts from piano to electronic keyboards and back, depending on the requirements of the moment (Brazilian percussionist Airto Moreira, saxophonist and flautist Ernie Watts, clarinetist Alvin Batiste, and electric blues-rock guitarist Mike Deasy all guest on various tracks, making the album something of a patchwork, and a fascinating if uneven document of walls falling down).

At the same time that he was working with Zappa, Duke began his solo career in earnest. Signed to the German label MPS, he released six albums between 1973 and 1976. These arrived during the High Fusion era, when players of unearthly technical skill were blending jazz, funk, and rock and in the process achieving far greater commercial success than their more acoustically inclined peers. He released one in 1973 (the double album The Inner Source), two in 1974 (Feel and Faces in Reflection), two in 1975 (The Aura Will Prevail and I Love the Blues, She Heard My Cry), and one more in 1976 (Liberated Fantasies). Though each album was unique, and there are sharp differences between them, they’re all clearly products of the same musical mind.

Though it was released in 1973, The Inner Source was recorded at two separate sessions in 1971, while Duke was in Adderley’s band, and was actually intended to be two albums—Solus and The Inner Source—but the label he was originally signed to, SABA, folded and became part of MPS. In any case, this is the “jazziest” of Duke’s early ’70s material. The Solus tracks are performed by a trio featuring bassist John Heard and drummer Dick Berk, and Duke shifts back and forth between piano and electric keyboards. The album opener, “Au-Right,” is straight funk, with a shuffling beat, but the next track, “Love Reborn,” is an acoustic half-ballad with loosely swinging drums and that early ’70s rubber-band upright bass sound. The Inner Source tracks feature the same rhythm section, but add percussionist Armando Peraza (of Santana), trumpeter Luis Gasca, and saxophonist Jerome Richardson. In order to fill out the horn section, Duke overdubbed trombone lines himself.

On 1974’s Faces in Reflection, Heard was back, but Berk was gone, replaced by Leon Ndugu Chancler. The music was more complex, though pop-friendly melodies emerged here and there, and Duke sang on several tracks. He also expanded his sonic palette by bringing in synths alongside the piano and organ.

Feel, also released in 1974, offered a surprise: two guest guitar solos from Zappa, credited as “Obdewl’l X,” likely for contractual reasons. It was recorded at Paramount Studios in L.A. with Heard and Chancler as the core band, bolstered by percussionist Airto Moreira and, on the title track, his wife Flora Purim on vocals. Duke’s own singing, most notably on “Love” (one of the two songs featuring Zappa), is soulful but also frail. Like Buddy Miles, he lacked the technical skill to truly put his lyrics over, but the occasional quaver or not-quite-there note ultimately added to the honesty of the performance as a whole.

The first of Duke’s 1975 releases, The Aura Will Prevail, is the most progressive item in his MPS catalog. Chancler remained behind the kit, and Moreira was present again, but bassist Heard was gone, replaced by Alphonso Johnson of Weather Report. While there are a few tracks with vocals, including the ballad “Fools,” it’s the instrumental music that’s the real draw. The connection to Zappa remains strong; in the album’s second half, the band plays the guitarist’s instrumental “Echidna’s Arf,” and follows that with “Uncle Remus,” a Duke/Zappa collaboration on which the keyboardist sings again.

I Love the Blues, She Heard My Cry is a more guitar-heavy album than its predecessor. Zappa doesn’t appear, but members of his band do, and the way many of the tracks are orchestrated, particularly the prominence given to marimbas and other percussion, echoes his work. Blues and funk legend Johnny “Guitar” Watson (who guested on Zappa’s One Size Fits All album the same year) duets with Duke on the title track, which is also the only straightforward blues tune on the record. Lee Ritenour pops up on the nearly metallic “Rokkinrowl,” and some of Duke’s regular collaborators, like Airto Moreira and Flora Purim, are present again for the jazzier, funkier instrumentals, as is drummer Leon Ndugu Chancler. The ballad “Someday,” which Duke sings in a falsetto style (and on which he played everything but the drums), became a radio hit.

Duke’s final MPS album, 1976’s Liberated Fantasies, is the weakest of the series, but it’s still interesting from a sonic perspective. His use of analog synths alongside the piano pushes the music into a territory that’s equal parts funk, fusion, and prog rock, with complex rhythms ticking and tumbling along behind him. Things start in an unpromising manner with “Don’t Be Shy,” a decent post-Sly Stone funk jam wrecked by puerile, annoying vocals from Zappa sideman Napoleon Murphy Brock. It also contains another radio-friendly ballad, “Seeing You,” which Duke himself disowned, though it’s not that much worse than, say, Earth, Wind & Fire‘s gloopiest material. Still, like all these records, Liberated Fantasies is multifaceted and throws a lot of ideas at the listener, some of them quite surprising, like “Tzina,” an instrumental excerpt from an opera(!) he wrote, and the title track, a Brazilian-influenced piece that closes the disc in a wave of explosive energy.

Seventies jazz-funk doesn’t get its due these days. The biggest names could really play, and they had a lot of fascinating ideas, fueled by coke, spirituality, and extremely broad listening. George Duke‘s MPS albums aren’t perfect, but each one is shockingly deep and rich, and well worth checking out.

—Phil Freeman

Stream a playlist of most of these albums, plus a few tracks with Ponty, Zappa and Adderley, on Spotify: