Like the previous four releases in Miles Davis’ “Bootleg Series,” the newest aims to offer an insider’s peek into the creation of the music. But this one goes deeper. Whereas the earlier sets presented live recordings as heard by concert audiences, this time, we’re in the studio as Davis and his so-called Second Great Quintet—pianist Herbie Hancock, saxophonist Wayne Shorter, bassist Ron Carter and drummer Tony Williams, together five of the most important musicians in all of jazz—work out the tracks that would ultimately become 1967’s Miles Smiles album (with some ending up on other projects). To be a fly on the wall as the band goes through its paces making music out of raw ideas is a gift; to hear the differences on master takes and alternates, sometimes subtle, sometimes not at all, is both instructive and fascinating. Some of the listening requires patience—there’s a lot of studio chatter (not all of it audible) and not all listeners will want to hear successive takes, usually two of each piece. For those who make the effort, though, the rewards are vast: Many, including “Nefertiti” (which would be released a couple of years later on its own same-titled album), “Footprints” and “Water Babies,” are Shorter compositions that would define his own genius as well as further Miles’ reputation as a creative