The short of it? The short of it! Hardly a tactful way to approach a project that has occupied eighteen years (so far), filled nine volumes that rise from 1,200 single-column pages to 1,700 double, each requiring an index of 100 pages and covering upwards of 10,000 jazz records. You–as I understand Americans say–do the math.

Actually, one guy did the math, very early on in the process, and he wrote to us in a fury. He had, we were told, just purchased the first edition of The Penguin Guide to Jazz (this in 1992, so geologically long ago that the book still bore the subtitle On CD, LP & Cassette), and he was writing to say that it was clearly impossible for two guys to have listened to all those records, let alone listened to them often enough to have formed a worthwhile opinion, let alone two Brits doing it! It was the kind of letter that staff on the London Times correspondence pages will tell you comes over the transom written in green ink, apparently a reliable giveaway of eccentricity and obsession. And this guy demanded to know whether Richard Cook and Brian Morton really were the authors or whether there was a clandestine team of jazz critics involved.

Sadly, the two guys are down to one guy now. My co-author Richard Cook, as distinguished a jazz writer as ever to grace the British press, succumbed to liver cancer last summer, aged just 50. We were always aware that we might be the ones charged with obsession or with a peculiarly British eccentricity, or even with a characteristically British arrogance, to think that we might attempt a comprehensive discographical survey of a music that always was–and still overwhelmingly is, for all you’ll read in some quarters–an American phenomenon.

I’ll come to the math in a moment, but we always had a laugh about stuff like this, and about those letters expressing outrage that we’d missed a single, small-label jazz record that had been available for five weeks in 1993, with a run of 500 copies. “How can you call yourselves jazz critics when you’ve never even heard of that great trombonist George W. Cheyney’s Bazaar Blues?” The first of my annual attempts to catch Richard out on April Fool’s was a letter (in green ink, natch) claiming to have seen at least two other suspicious characters listening to jazz and scribbling notes in clubs called the Grassy Knoll. There was also a gag involving Jack Ruby and Ruby Braff, but it was too convoluted to recall. We figured that if the Brits were eccentric, the Americans liked a conspiracy theory.

In reality, and given a tail-thrust of obsession, there’s nothing suspect about the figures. When we began working on the first Penguin Guide in 1991, Richard and I had been listening to jazz since our teens and writing about it in papers and magazines for more than a decade. We felt, rightly or wrongly, that we knew our way around. In those days of LP durations and relatively few jazz imprints, we could reasonably claim that, first of all, our coverage was pretty comprehensive (the egregious omission of George W. Cheyney apart) and, more important, that our views weren’t simply off-the-cuff thumbs-ups or thumbs-downs.

Devising a scale of rankings was a side of the project that both of us, interested in a more contextualized kind of reviewing than what has become the current “download this” imprimatur, found very difficult. We were initially resistant to a system whereby we, in our authority or arrogance, assigned stars to the great stars of the music. Besides, how did a three-star Louis Armstrong or John Coltrane record convert to a three-star Bill Charlap or Tierney Sutton record? By giving some three-score records five stars–or strictly a crown–were we trying to establish some kind of canon, or Great Tradition? In time, we recognized that these were simply useful devices, visual guides. We also began to recognize that as the jazz-recording sector metastasized, mostly in the area of out-of-copyright reissues, a principle of selectivity became not only essential but also desirable. Ironically, as the market becomes ever more choked with box sets bearing the Definitive or Complete headers that are catnip to reissue labels and fans alike, we have had to drop any similar claim. Because both the amount of jazz recordings now available is uncoverably huge and the forthcoming edition is, for the reasons explained, the work of one guy rather than two, the coverage has to become more selective.

Of all the awful things that came with Richard’s death–and simply talking to him about the music, confirming an impression or arguing a point was the first casualty–one of the most galling is that it’s now impossible to disguise who wrote what. By definition, anything new that appears after the 2006 edition is down to me, warts and all. Of course, the book contains a lot of Richard’s writing, and it was our great amusement to speak to friends and colleagues, all of whom “knew” either by instinct, some imagined personal reference or some arcane deep-textual process, who had written what–and to learn that they were invariably wrong.

It was causally assumed that we divided the known world between us, like Napoleon and William Pitt, or like the two history professors at my university, one of whom went up to 1660, the other from 1661 to the present. There was no such divide. We both began listening to classic jazz on record–Morton, Bechet, Pops–and hearing British avant-garde jazz and fusion in live situations, working forward and backward from there until we met around bebop. Richard and I met–though we may have brushed shoulders often before and we each knew who the other was–at a Jackie McLean concert, which seemed just about right. When the book came along, we divided everything ad hoc: classic stuff, swing, bebop, hard bop, postbop, free, the small amount of fusion that sneaked in, singers. I used to tell the Nosy Parkers who wanted to know who wrote a particular entry that all the cricketing metaphors were Richard’s and all the boxing ones were mine, but of course over time I started to mention googlies and Chinamen (don’t ask) and Richard threw the odd punch himself, just to throw things off. References to malt whiskey and horse-racing were shared, a common obsession, though as a part-gypsy Scot I claim absolute authority on both subjects. Richard was a wizard jazz writer, but he couldn’t pick a winner.

This may sound like an extended plug for a forthcoming book, and I don’t doubt that it is. It’s also meant to be an affectionate tribute to a friend and colleague and, less personally but just as seriously, an attempt to ask certain questions that perhaps didn’t need to be asked before last September. Like: What’s the nature of a writing collaboration, when you don’t sit side by side (Richard was in London; I in Scotland) and agree on every word and every verdict? What’s the role of a book like this when you can find a thousand verdicts on the Internet, with everyone his/her own critic? Is a book like this as absurdly unfinishable as Mr. Casaubon’s Key to All Mythologies, something you keep adding to hopelessly and for all time?

There are other interesting questions: how do you restore the debased coinage of critical praise (the language of dispraise always being far more vivid) and find new words to describe the sound of a tenor saxophone? Metal fatigue can make bridges collapse and planes fall from the sky; adjective fatigue awaits anyone who writes a book like this. Then: what’s the nature of a brand when half the brand is gone? Many young Brits have had the le Carré-ish experience of striding into a London tailor called Wallis & Simpson or some such, looking for one of Mr. Wallis’s Norfolk jackets, only to be told murmuringly that, ah, Mr. Wallis passed away in 1938, but young Mr. Simpson would be delighted to measure you up, sir.

As things now stand, with the ninth edition in the presses (and available in stores in November), and the future beyond that uncertain, I’m both measured and measuring. At bottom, there’s only one reason to do a book like this, and that’s love of the music. And, of course, like waiting for the Messiah, it’s steady work.