Once asked what instrument he might play if not the Hammond organ, Dr. Lonnie Smith shook his head. Nothing? Hammond, he said. Smith was steadfast that way: In a 50-year-plus career, he rarely deviated from the blend of soul, jazz and gospel he helped develop in the late '60s. But you couldn’t really call him a purist either. If anything, his music—progressive but intuitive, mixing the earthiness of '50s R&B with the cosmic sensibility of post-psychedelic jazz—helped lay the foundation for hip-hop, which he openly supported. He recorded album-length tributes to Jimi Hendrix and Beck, collaborated with Iggy Pop, and has been sampled by A Tribe Called Quest, Madvillain, Wu-Tang Clan and others—a résumé that reflects both his musical openness and his indifference to category. He died in September 2021 at the age of 79.