Imagine a story where a guy is invited to watch Bob Dylan in the studio one day in 1965. Despite not knowing how to play the instrument, the guy sits down at the organ and comes up with what would become the signature part of “Like a Rolling Stone.” Dylan likes the part so much he asks the guy to join his band. A few years later, the same guy plays the French horn on the Rolling Stones’ “You Can’t Always Get What You Want.” He also plays with Jimi Hendrix, the Who, Tom Petty, and George Harrison. The same guy, working as a record producer and talent scout, signs both the Zombies and Lynyrd Skynyrd.

Sounds like an improbable story, doesn’t it? But that’s just part of the life history of Al Kooper, perhaps the most important rock musician of the ’60s who is not today a household name. Some of the projects he was most intimately involved in — like his band the Blues Project and the Super Session album he cut with Mike Bloomfield and Stephen Stills — were influential and highly popular in the ’60s but little remembered today. And his solo career never seemed to get off the ground, even as seemingly everyone he worked with was becoming a legend of classic rock. Kooper was even booted out of Blood, Sweat & Tears, a band he founded.

Still, for decades Kooper has never stopped doing important work in music, whether as an educator, a producer, or a performer. In 2001, Kooper lost most of his vision, but he didn’t let that stop him either. As he told the San Francisco Chronicle, “I thank God it wasn’t my hands or ears.”

AL KOOPER, AcousticMusicSanDiego, Friday, January 9, 7:30 p.m. 619-303-8176. $25.