Hathaway released just three solo studio albums, a record of duets, and the movie soundtrack Come Back Charleston Blues before his death—ruled a suicide—in January of 1979. The first of these albums came out in 1970, the last in 1973; after that, depression crippled Hathaway’s musical output. Some additional duets he recorded with the singer Roberta Flack were put out posthumously. So Hathaway may not have produced at a high volume. But, as shown in the new box set Never My Love, he was efficient.

The album that marks Hathaway’s clearest stake to excellence is 1970’s Everything Is Everything, a tightly unified work that adeptly mixed a gritty funk low end, soaring gospel ballads, and orchestrated soul. It included political commentary (almost a year before What’s Goin’ On), impressive originals, and formidable covers of standards—“Misty”—and songs by Ray Charles and Nina Simone. Hathaway had some of the vocal gravity of Stevie Wonder, and believed firmly in the power of call and response. When he wasn’t singing opposite Roberta Flack, he often stood out against a large cadre of backing vocalists.

Six of Everything Is Everything’s 10 tracks make it on to Never My Love. This includes “The Ghetto,” a radical take on political soul: electric-keyboard-driven, Latin-inflected, relentless. The lyrics mainly consist of Hathaway repeating “The Ghetto” over and over. Curtis Mayfield or Gaye linked their politics to stories of drug-dealers and veterans; Hathaway eschewed narrative in favor of repetition, one of pop’s most effective weapons, demanding notice through single-minded focus. Funk draws much of its potency from recurring themes as well, and Hathaway just fused medium and message. The live version—one of the four discs is devoted to a performance in New York—stretches “The Ghetto” out to more than 14 minutes, as Hathaway solos furiously, and the audience joins in clapping in double time.

The ‘70s was also a fertile period of interplay between funk, soul, and jazz, as the giants of R&B drew on the looser, longer, more improvisatory textures of jazz—and used jazz players—when making their own music. (Jazz also found influence in funk; see Miles Davis.) Hathaway’s “Come Back Charleston Blue,” all smooth keys, shows Hathaway ably taking a turn into bluesy-jazz vocals, while “Valdez in the Country,” mulls over a riff again and again, happily undecided as to how it should be played best.

What if Hathaway hadn’t suffered from brutal bouts of depression that eventually took his life? The unreleased material shows a few possible trajectories for the artist. In “A Lot Of Soul,” Hathaway applies his skills to country. He arranged Willie Nelson’s funkiest album, Shotgun Willie, and it’s too bad that some smart producer didn’t encourage Hathaway to record a full-length in Nashville.