There aren’t enough column inches on Earth to adequately describe the impact of Alan and Marilyn Bergman, whose lyrics are currently being celebrated by Michael Feinstein (and special guests) in a two-week run at Feinstein’s at Loews Regency. But one would have to begin with how much their songs have dominated the intelligent pop music of the last 40 years, and even provided a lifeline to the great traditional pop and jazz singers in the latter parts of their careers: The canons of Tony Bennett, Frank Sinatra, Rosemary Clooney, and many others would be considerably poorer without them.

In the 1960s and ’70s, the Bergmans achieved the near-impossible feat of sustaining the quality of their predecessors — including Johnny Mercer, Sammy Cahn, Ira Gershwin, and Dorothy Fields — in an era when mainstream pop music was flowing in an entirely different direction. There were other songwriters producing first-class music in the 1970s and beyond (such as Cy Coleman, Stephen Sondheim, and Jerry Herman, the “big three” of late 20th-century music), but their songs were increasingly intrinsic to specific musical theater plots and characters. Only the Bergmans and their various composer collaborators routinely produced pure pop songs that told a complete story entirely on their own.

In his patter during the opening show on Thursday night, Mr. Feinstein pointed out that each of the Bergmans’ songs expresses “a different point of view and a different attitude,” yet there is a remarkable consistency to their music. In fact, the very concept of consistency is kind of the point.

The Bergmans’ lyrics owe a lot of their brilliance to a synchronicity that has to be more than a coincidence. Both lyricists were born in Brooklyn and were mentored by giants of Tin Pan Alley. Alan (born 1925), was a protégé of Leo Robin, Marilyn (born 1929) learned from Bob Russell, and they were united by the sagacious veteran composer Lew Spence. In the late ’50s, the Bergmans, who began working together in 1957 and were married in 1958, launched a string of jukebox hits, such as the Sinatra classic “Nice n’ Easy” and the ubiquitous “Yellow Bird.”

From there, special projects and specific assignments flowed into the 1960s. There was Jo Stafford’s excellent concept album, “Ballad of the Blues,” and 1967’s “Make Me Rainbows,” with John Williams. But it wasn’t until the late ’60s and a partnership with the French composer Michel Legrand that the Bergmans began turning out full-dressed standards with seeming effortlessness. Together with Mr. Legrand, who had already landed several substantial hits (notably “Watch What Happens”) in the ’50s, the Bergmans hit their stride with the Mozartian “Windmills of Your Mind,” “What Are You Doing the Rest of Your Life?,” and “Summer Me, Winter Me,” in 1968-69, and followed them with “Pieces of Dreams” and “The Summer Knows” in the early ’70s.

Having reached middle age by this point, the Bergmans began writing songs that appealed to a generation of performers and listeners the same age. It was a brilliant stroke, in that nearly all the major vocalists of the glory years were themselves ready for material that reflected the experiences of living and learning — songs that married contemporary craft with a classic sonic quality. They were instant standards. As Mr. Feinstein joked on Thursday, “You will not hear these songs being done by anybody associated with ‘American Idol’ — not for a long time.” In an era when the music business was falling over itself to make pop culture ever more youthful, the Bergmans prevailed by doing just the opposite. Their songs reflected the hopes and concerns of grown-ups. They rarely wrote about falling in love. They were about consistency and commitment — being in it for the long haul.

Nearly every classic Bergman song, as epitomized in their 1982 masterpiece, “How Do You Keep the Music Playing?,” is about sustaining a relationship and keeping the music playing for as long as possible. In “Never Say Goodbye” (especially as sung by Clooney on “Demi-Centennial”) and “The Trouble With Hello Is Goodbye” (a rarity recorded by June Christy), they posited that no relationship is worth starting unless the participants are prepared to stay the course. “Summer Me, Winter Me” (truly essential Sinatra) and “I Have the Feeling I’ve Been Here Before” (with a melody by Roger Kellaway and the great line “the joke November makes of May”) use the seasons as metaphors for dependability, and “You Must Believe in Spring” employs nature as a reference point for emotional stability. Another underappreciated jewel of a tune, “I Was Born in Love With You” (the marvelous 1969 recording by Peggy Lee has just been reissued on “Where Did They Go?”), makes the point that commitment begins before birth. That’s why their sad songs are proportionately sadder: When these relationships end, it takes more than a drink to get over it.

Mr. Bergman tells a joke about a friend who got married to “What Are You Doing the Rest of Your Life?,” separated to “Where Do You Start?,” and divorced to “The Way We Were” (a major hit for the team, although Marvin Hamlisch’s tinkly tune hasn’t dated well). “Where Do You Start?” is an amazing song for a couple who’ve been together since the Eisenhower era, as everyone who has taken an unplanned trip to splitsville and was convinced that the Bergmans were eavesdropping on them will attest. “I Will Say Goodbye” turns sadness (“It will be as though we had never met”) into a tragedy of mythological proportions (“I will not look back or I will turn to stone”).

Some decades ago, when I was a tender and callow fellow in my 20s, I couldn’t see the point of these songs. It was beyond me why anyone would want to sing them while the music of Harold Arlen and Cole Porter still existed. Many years and relationships later, I get it but good. There’s no one remotely in the same league as Alan and Marilyn Bergman when it comes to using music as a lesson for how to love someone for a lifetime.

wfriedwald@nysun.com