Mark Wilder, senior mastering engineer for Sony Music Studios, looked expectantly from John Atkinson to Bob Saglio to me and asked, "Are you ready?" As it had been my inquiry that had resulted in this mind-boggling, once-in-a-lifetime, peak-experience get-together, and as no one else was speaking up, I replied, "As ready as we'll ever be."

Weeks earlier, I had asked Sony whether I could ask a few questions of the mastering engineer who had made the DSD transfer of the master tapes of Miles Davis' Kind of Blue, from which the SACD editions were made.1 In due course, I received a flabbergasting e-mail invitation from Wilder—as low-key, unpretentious, and generous a chap as you could ever hope to meet—to pick a convenient date to drop by to hear the master tapes.

Out of genuine affection for John Atkinson, and admittedly out of some vestigial sense of political acumen, I responded that I could not imagine accepting such an invitation without asking if my editor-in-chief could tag along. My friend Bob Saglio agreed to share the driving chores. For its part, Sony transferred the priceless master tapes from their secure remote storage facility to their Manhattan mastering labs.

When Bob and I arrived, we were greeted by Mark Wilder and a fairly agog John Atkinson, who exclaimed that he could not believe that he was looking at the original tape boxes and recording-session log sheets from 1959. I goggled myself. Carefully examining the log sheet for the first session, I told Wilder that he had to understand that for us, this was like being allowed to look around the Vatican Library after closing time. He nodded comprehension, and quietly said, "I have the best job in the world."

About those tapes

According to Mark Wilder, Columbia's practice at its 30th Street studios in 1959 was to use four tape decks simultaneously: a prime mono deck and a mono backup, for mono LP release; and a prime three-channel deck and a three-channel backup, for stereo LP release. The mono tapes have since disappeared. The backup three-channel tapes (the ones we heard) were sent to the vault, where they rested untouched from 1959 until 1992.

The tapes from the prime three-channel deck were edited with razor blades to remove test tones, slatings, and session chatter, and to provide the spacings between tracks. All of the numbers on Kind of Blue are complete takes—there were no edits within pieces. (However, the oft-repeated claim—which appears even in the 2004 documentary Made in Heaven—that the album contained the first complete take of each number, is an overstatement. "Flamenco Sketches" had two complete takes, the second of which was chosen for the original release.) The three-channel edited master tapes were then mixed down to two-track tapes that were used to cut the stereo LP lacquers, with the fadeouts at the ends of tracks applied manually as the lacquers were cut.

It was not until 1992 that Wilder discovered that the prime three-channel deck had been running slightly slowly during the first session, with the result that on the LPs and CDs made from it, the numbers on side A (the first three tracks) played slightly sharp in musical pitch. By the time of the second recording session, seven weeks later, the prime three-track deck had received some maintenance, so the numbers on the LP's side B were recorded at the proper speed. To get the proper pitch without adjusting the playback deck's speed, and knowing that the backup tapes had never been played, Wilder used them for the 1992 Columbia Mastersound SBM Gold CD remastering. Those tapes have been used ever since, including for the SACD releases.

Wilder had set up for us an Ampex ATR 102 three-track tape deck to play the simultaneous-safety three-channel masters through a simple mixer, with the center track split right and left for two-channel stereo playback, then to a Spectral stereo amp and two Duntech Princess speakers.

His mastering room was very carefully set up. In addition to the expected acoustical treatments, the speakers themselves sat on 600-lb concrete blocks, to compensate for being on the third floor of the building. Pennies had not been pinched for his equipment; in addition to brand names from the pro audio world, he had EMM Labs (Ed Meitner) digital and Tim de Paravicini analog equipment. Along the way, Wilder answered my original question that had set things in motion: The SACDs derive directly from analog tape by way of EMM Labs DSD equipment. There was no PCM interstage, and the Kind of Blue SACDs are not repurposed "Red Book" data.

Wilder pushed Play. We heard session producer Irving Townsend say, "The machine is on . . . here we go." At that point, I realized how glad I was to be in the company of friends. I had suddenly become unsure I could ever convey to someone who had not been there the frisson, the sense of rolling up a window shade and looking out a window at the early afternoon of March 2, 1959.

To say the least, it sounded extraordinarily immediate. The stereo SACD is, in contrast, two generations removed: first, a three-track to two-track analog tape intermaster (to allow for sequencing the tracks), and second, the SACD itself. You can't get closer on this earth to what happened at the Kind of Blue sessions than we did. But my making you envious about our good fortune does none of us any good. I will just make a few observations about that listening session, then move on to letting you know about resources that can help you deepen your appreciation of Kind of Blue.

Because Kind of Blue was recorded in multitrack mono, without the use of any real stereophonic microphone techniques, the instruments appear in fairly constricted left, center, and right locations. The microphones were, according to Ashley Kahn's book, Telefunken U-49s—can't complain about that. But the center image, Davis' trumpet plus Paul Chambers' bass, was solid as a rock—so shockingly solid that at first I thought the center speaker was on. It wasn't. (A trap for the unwary: Between the first recording session, which accounts for the album's first three tracks, and the second, which accounts for the last two, the sax players swap track assignments. For the first three numbers, tenor saxophonist John Coltrane is on the left and alto saxophonist Julian "Cannonball" Adderley is on the right; for the last two, Adderley is on the left and Coltrane on the right. The positions of the other musicians in the soundstage are consistent throughout the album.)

Mark Wilder even let me play with the mixer's faders a bit. Pulling down the outer tracks, I swear I could hear the sonic signature of the surface of the walls of the concrete echo chamber in 30th Street's basement. Although only Davis and Chambers' track had a send and return to and from the echo chamber, there was some degree of leakage from the other instruments. Perhaps that helps account for the recording's naturally ambient sound.

While we are all conditioned to hearing the tracks in the order of the released LP, track 2, "Freddie Freeloader," was recorded first, because that was the only track on which Wynton Kelly was to play. In similar fashion, "Flamenco Sketches," the album's final track, was the first piece recorded the day of the second session (April 22, 1959). "All Blues," the next-to-last track, was recorded last. Doubtless by coincidence, the recording sessions began and ended with blues.

Bill Evans' claim in his original liner notes that all the pieces were totally unfamiliar and totally improvised is to some degree fairy dust. Drummer Jimmy Cobb later recalled having played "So What" in live performances before the recording session; "All Blues" had been evolving for at least six months, with input from Gil Evans; the introduction to "So What" was most likely written by Gil Evans rather than improvised by Bill Evans; and "Flamenco Sketches" owes much to Bill Evans' previously released "Peace Piece." Still, the most deeply impressive aspect of this listening session was that it demonstrated that, for the most part, the musicians were feeling their ways, coming up with ideas only seconds before they had to play them.

To hear "Flamenco Sketches" evolve from the first complete take, through several incomplete attempts, to the final take, which is the one that was used for the original release, was enlightening and humbling. (The first take, the only complete alternate take from the two sessions, was used as the bonus track on releases from 1992 on.)

Books, etc.

As the master tapes began playing, I pulled from my briefcase the resource that has most helped me deepen my appreciation of Kind of Blue: a hardbound volume of Kind of Blue scores, with all the solos and horn-ensemble sections transcribed, note for note. I opened it to "Freddie Freeloader," and to say that John Atkinson was engrossed within seconds would be an understatement. The next day he went online and bought a copy. (Be sure to get the Deluxe Edition.)