When the saxophonist and composer Steve Lehman realized he wouldn’t be able to travel from Los Angeles to Brooklyn for his mother’s 80th birthday this month, he decided to send her a sonic greeting instead. Recording in his car during breaks from home schooling his children, Lehman produced an EP of solos, “Xenakis and the Valedictorian.”

Appropriately, when Lehman was a child, his mother, Sheila, introduced him to experimental composers like Iannis Xenakis. (She played the composer’s “Bohor” at an early haunted-house party.) Now, her son has repaid her aesthetic modernism in turn.

Lehman’s regular label, Pi Recordings, is releasing his short but stirring EP on Friday as part of a campaign to raise money for musicians who have lost income because of the pandemic. The post-bop tradition is in evidence most prominently on the track “2 Gears/13 Satellites.”