Columbia wisely recorded set after set of what was just a normal weekend at the start of the 1960s for the stellar Miles Davis quintet—April 21 and 22, 1961 to be exact. The choice was made to do it in San Francisco, a city the trumpeter had a positive affinity with, and where his favorite critic lived: Ralph J. Gleason, who wrote the original liner notes for this set. The idea was to capture the energy, thrills and moods that went into his club show at the time—all powered by the fleet agility of one of the most amazing rhythm sections of that time—or any for that matter: Kelly, Chambers, and Cobb (the ballad “Love, I’ve Found You” is the trio’s star-turn on this recording.)

The new wrinkle here is tenor saxophonist Hank Mobley, already established by way of his Blue Note recordings, his warm tone and post-bop phrasing nudging the music back to the familiar feel of the 1950s. Miles, opening his solos with surprise and drama, restlessly points somewhere forward. The thing is they are both great at what they do—as is Kelly’s sophisticated piano work—and the tug between them all sparks the music, finding a place for all voices in Miles’ favorite standards of the day (“All Of You,” “On Green Dolphin Street,” and especially “If I Were Bell”) as well as in older bebop and blues tunes (Sonny Rollins’ “Oleo,” Monk’s “Well You Needn’t,” Miles’ “Walkin’”) and in new originals—like “No Blues” (powered by Cobb’s cymbal beat) and the debut of “Fran Dance,” Miles’s tribute to his wife Frances. That’s her on the original cover, wondering where Miles is going with a cape-like garment on.

Over the years, the music from this weekend—originally release simultaneously as two separate LPs—has been repeatedly collected and released, and praised each time for its rhythmic charge and for being true to the spirit and even rough edges (dropped beats, slips, miscues) of any live performance.