Those of you with only four different versions of “Still Crazy After All These Years” in your record collection can rest a little more easily today. Warner Bros. Records has just released “The Essential Paul Simon,” a two-CD, 36-song set on sale for $23.97 on Amazon.com.

This marks the ninth collection of Paul Simon’s hits now available for purchase. Other Paul Simon best-of CDs include “The Paul Simon Collection,” “The Paul Simon Anthology,” “Paul Simon’s Greatest Hits,” “Negotiations & Love Songs,” “The Studio Recordings: 1972–2000,” “Paul Simon: Greatest Hits, Etc.,” “The Paul Simon Songbook,” and “Paul Simon: Collected Works.” And don’t forget the seven different versions of Simon & Garfunkel’s hits on the market. To supplement your copy of “Simon & Garfunkel’s Greatest Hits,” there’s “The Best of Simon & Garfunkel,” “The Essential Simon & Garfunkel,” “The Very Best of Simon & Garfunkel,” “Simon & Garfunkel: Collected Works,” “The Columbia Studio Recordings: 1964-1970,” and “The Definitive Simon & Garfunkel” to round things out.

If you already own a full set of these albums and you’re still not feelin’ groovy, please see your doctor.

It wouldn’t be fair to blame Mr. Simon alone for this alarming surplus of vanity vinyl. He can’t help that he has been churning out hit songs since the mid-1960s, and reinventing himself in new musical forms at regular intervals. It’s not his fault that he writes classic ballads you want to hear again; remember, “The Sound of Silence” appeared on the first Simon & Garfunkel album in 1964, “Wednesday Morning, 3 a.m.” Was Mr. Simon guilty of any crime when “The Sound of Silence” reappeared in 1966 as the title song of their second album?

Let’s face it: Mr. Simon knows what sells, and doesn’t mind if the market keeps coming back for more. Plus he understands how to blend sweet pop melodies with provocative, reference-laced lyrics in original ways, creating new hits to join forces with his established classics. His last Billboard-ranked single was “Father and Daughter” from the “Wild Thornberrys” soundtrack in 2002, which also got an Academy Award nomination for best song. Naturally, that tune has just shown up on the new “Essential Paul Simon” collection.

No one should begrudge Mr. Simon his continued success at selling the Simon songbook. Unlike his erstwhile partner, Art Garfunkel — the duo’s sweet-voiced soprano harmonist now best known for his multiple marijuana arrests — Mr. Simon has advanced his musical talents and interests in ways that have earned him 12 Grammy Awards, including three for best album. In 1986, with “Graceland,” Mr. Simon demonstrated an affection for African rhythms that would dominate his recordings for years to come; his success and influence stemmed from his regular insistence on learning and growing as an artist and composer.

But like so many other writerperformers who came to fame in the 1960s and ’70s, Mr. Simon has had to contend lately with an utterly transformed marketplace for music — one that puts less emphasis on albums, and more on hit singles sold on iTunes. The music industry that once elevated Simon & Garfunkel to superstardom with the release of an album (“Parsley, Sage, Rosemary and Thyme,” a Columbia release in 1966, reached number four on the Billboard charts) now considers itself lucky if an album sells a tiny fraction of what used to be considered a hit.

Recording artists now make most of their money in live performance and downloads, and that has created new pressures for album-oriented acts like Mr. Simon. The recent release of Paul McCartney’s “Memory Almost Full” exclusively in Starbucks showed that even former Beatles must seek out new ways to compete for the shrinking audience that still wants albums. Only last weekend, Prince angered Sony Records by handing out three million copies of his latest release, “Planet Earth,” for free with a copy of England’s Sunday Mail, citing as his reason that he makes most of his millions from performing. It only costs $9.99 on Amazon.

To keep selling albums, artists like Mr. Simon must now fall back on their recognizable classics, in the same way publishing houses insure their economic health by maintaining a “backlist” of hardy perennials for sale. In the final weeks before it closed last winter, Tower Records resembled little more than a remainder bin for “Greatest Hits” collections: Led Zeppelin competed with Creedence Clearwater Revival a pointed reminder of how a oncemammoth industry had lost its economic muscle.

We probably ought to credit Mr. Simon for so cleverly repackaging his old hits in so many distinctive wrappings. And given the economics of CDs, it’s likely that Warner Bros. will make enough money on the new packaging to pay the comparatively miniscule costs of “remastering” old recordings and slapping them on a disc. That will squeeze some profit from the Simon library yet again, and maybe even entitle Mr. Simon to record an album of new material for Warner Bros. one day soon. None is currently planned.

In the 39 years since the release of “The Graduate,” the 1968 movie with the Simon & Garfunkel soundtrack that made simultaneous movie and musical history, Mr. Simon has arguably become one of a generation’s most venerable nostalgia products. We can likely expect the day very soon when we’re all implanted with a Paul Simon “best-of” chip in our brains. In the meantime, I’m looking forward to the next Warner Bros. CD collection, tentatively titled “The Sounds of Simon: 50 Ways To Sell Your Songbook.”