On the second album by Miles Davis’ second great quintet, they started building upon the achievements of 1965’s E.S.P. The music walked a tightrope between relatively structured modal grooves and melodic solos, and improvisations that nudged up against the avant-garde. The music frequently strips away familiar elements, even ones considered vitally necessary — on three of the album’s six tracks, pianist Herbie Hancock plays only with his right hand, entirely dispensing with the chords pianists typically delivered via the left hand. This leaves the rhythm and structure entirely up to bassist Ron Carter and drummer Tony Williams, who seem to be rocketing in all directions at once. It’s not all high-speed, high-tension adventure, though. The ballad “Circle” is gentle and beautiful, shifting slowly and organically while somehow still maintaining just enough of its essential structure to keep the listener from ever feeling lost.

Even more than on E.S.P., saxophonist Wayne Shorter was the dominant compositional voice within the group, bringing in three pieces, including one (“Footprints”) he’d recorded on his own album, Adam’s Apple, for Blue Note a year earlier. That track, and two others — “Gingerbread Boy” and “Dolores” — made it into the band’s live sets, too. Recorded in only two days, Miles Smiles has a slightly rough feel that gives the music even more energy; the band sounds like they’re ripping through the material in as few takes as possible, so they can get back on the road. And yet, as the album’s title suggests, they still want to win people over. This isn’t a dry, austere record aimed at documenting their artistic genius — it’s meant to entertain as many people as possible. It’s one of the most open albums of Davis’ career, and an ideal entry point into this group’s catalog.