The toughest part about getting married, which I did a few weeks ago, wasn’t making the commitment, but repurposing my apartment for a major lifestyle change. As I tried to consolidate my record library into a smaller space, I experienced two minor epiphanies: First, as I move all 15,000 LPs, 10,000 CDs, and Lord knows how many music books from one room to another, the prospect of someday having all that music on a hard drive is a reassuring one. Second, when I re-attached my stereo system, I realized that I hadn’t used my CD player in months, and I decided at that point to retire it. I do 99% of my listening on the computer, and it’s no longer worth the valuable Manhattan real estate to keep the CD changer front and center.

Universal Music is at least one step ahead of me: Last summer, it became the first of the major media corporations to make a significant number of classic jazz albums (as well as classic classical) available only as downloads — not sold on CD or any other physical form (even over the Internet or mail order, as Mosaic Records does) — and principally from its own Web site, as opposed to Apple’s iTunes store.

Universal is offering an interesting mix of selections, including minor releases by major stars, such as “Collages,” Duke Ellington’s curious 1967 collaboration with a Canadian jazz orchestra and probably the least Duke-ish record ever made, and “Buttercorn Lady,” a pop-ish 1966 live set by Art Blakey featuring the trumpeter Chuck Mangione and pianist Keith Jarrett as members of the Jazz Messengers (it’s a little like hearing Toscanini with Yanni and Stockhausen as guest soloists).

There are also all kinds of interesting releases that fell through the cracks — such as “The Hub of Hubbard,” a 1969 concert from Germany by Freddie Hubbard, and two albums by tenorist–composer Benny Golson, “Free” and “Take a Number” — that are otherwise available only as part of Mosaic’s Jazztet box.

Personally, I’m jazzed to acquire a blazing 1962 live set (spread over two albums, “Late Spot at Scott’s” and “Down in the Village”) by Tubby Hayes, an aggressive, Rollins-esque British tenor player whose work is hard to find outside Britain. It’s a cinch that I’ll never hear this music any other way, and I’m grateful for the chance to download it.

I’m something of an obsessive when it comes to adding cover art to my hard drive library, so I was relieved when most of the covers to these albums were added automatically by iTunes (a feature that became standard with version 7.0). But in listening to, say, the Freddie Hubbard set, I was going nuts trying to figure out who the saxophone player was — it didn’t sound like James Spaulding or Joe Henderson or any of Mr. Hubbard’s usual front liners. Similarly, the Tubby Hayes set includes a lovely ballad reading of “But Beautiful” as a vibraphone feature, but it gave me pause when Tubbs announced the band and neglected to mention a vibraphonist.

Enter Tom Lord and his new online jazz discography. Thanks to Mr. Lord, I now know that the vibraphonist was Hayes himself — I had forgotten that he was perhaps the only major tenor saxophone-vibraphone double in jazz history. I also know that the tenor player with Freddie Hubbard is Eddie Daniels, usually known as a clarinetist with contemporary big bands.

I don’t imagine that fans of Ja Rule or the Berlin Philharmonic need to know the complete personnel of the backing bands as they listen, and I’m not saying that all jazz fans are as nerdy as myself (thank God). But trust me, even a casual jazz fan doesn’t want to hear a trumpet solo on an Art Blakey recording without knowing whether it’s Lee Morgan, Clifford Brown, or Al Hirt. It’s unlikely that Universal and iTunes are going to include this information in their downloads anytime soon (although there is plenty of room for such text in the metadata).

In the last 15 years, Mr. Lord has established himself as the pre-eminent jazz discographer, especially in the technological sense. He began offering his massive jazz discography as a series of expensive (and, cumulatively, weighty) printed paperback books in the early ’90s before offering the entire 34-volume series on CD-ROM about five years ago.

Now, he’s made an even more important breakthrough by making the whole works available online (lordisco.com). Mr. Lord’s timing couldn’t be better: In the ’90s, when a complete set of the printed edition cost more than $2,000, I would have thought that the Jazz Discography was only for hardcore geeks like myself. But now, with the entire music world moving away from tangible formats like CDs (with informative booklets) and into downloads (with no information whatsoever), the online jazz discography is necessary for any but the most casual listener. The major statistics of the work continue to escalate: more than 175,000 sessions going back 110 years to the dawn of sound recording itself, and more musicians and song titles than one can shake a drumstick at (although it would be nice to have the composer credits for all those songs, but you can’t have everything).

The major addition to the Web-based discography is a built-in feature that allows users to catalog their individual collections — something I’m not about to start doing at this late stage of the game, with 30,000 LPs and CDs to worry about. For me, the most essential asset of the online version is the speed with which Mr. Lord can make additions, updates, and corrections: Traditionally, there has been a lag in discographies (or any printed reference work). But now I can look up a recent album, as I did with Harry Allen and Joe Cohn’s “Guys and Dolls,” released a few months ago, and be delighted to see that Mr. Lord has included all the details. He has also included a separate section that shows the latest changes.

The grandfather of all jazz discographies, Brian Rust’s “Jazz Records 1897–1942,” only cataloged 78 RPM entries, even though it wasn’t published until well after the 78 era. Likewise, Mr. Lord’s new project arrives, fittingly, at the twilight of the compact disc era, which raises a question: How is Mr. Lord going to keep track of legally offered online downloads, not only in the case of re-issues, like the Universal offerings, but new performances never made available elsewhere? Do they not deserve to be acknowledged and cataloged as well?

What’s ultimately needed is for the Jazz Discography to be somehow conjoined with iTunes, the iTunes store, the Universal Music site, eMusic, Rhapsody, Amazon, and the other online music purveyors, so that one can research, purchase, hear, and enjoy any and every slice of this music that’s ever been recorded. That would propel us forward us into a whole new techno-dimension of jazz appreciation such as only Sun Ra could have imagined.

wfriedwald@nysun.com