Recently, the Takacs Quartet gave a recital at the University of Colorado Boulder. In many ways, it could have been perfectly routine: some Béla Bartok and Ludwig van Beethoven before an adoring audience at the college where the group has taught in residence since 1986.

But the Takacs simply does not do routine.

The Beethoven was a perfect example, an exceptional account of the Opus 135 Quartet that was astonishingly vivid even when watched on a livestream. You could have taken any of its four movements and written pages in their praise. Perhaps what struck most, though, was just how constantly and generously each of the players — Edward Dusinberre, first violin; Harumi Rhodes, second violin; Richard O’Neill, viola; and Andras Fejer, cello — was physically and aurally in dialogue with the others, and through them, the listener.

It’s that ability to communicate, among many other talents, that makes the Takacs the essential quartet of our time. It’s also one of the qualities that has kept the group so identifiably itself as time has passed: The quartet marks its 50th anniversary this year.

The name Takacs has become a synonym for assured, collective excellence, but its story is one of evolution, not stasis. Read either of Dusinberre’s eloquent memoirs relating the history of the quartet, and it becomes clear that it has been a personal drama, played out through the scores that its members rehearse and perform.

Time certainly has remade the Takacs. Only one of the four young Hungarians — Gabor Takacs-Nagy, Karoly Schranz, Gabor Ormai and Fejer — who stepped into their first lesson in communist Hungary, ready with a Wolfgang Amadeus Mozart quartet, remains. Both Roger Tapping and Geraldine Walther, the violists who followed Ormai in turn, have come and gone.

“Changing a player in a string quartet is a trauma that must be played out under the watchful eye of an expectant public,” Dusinberre has written. Some of those traumas have been more painful than others, above all the death of Ormai from cancer, in 1995. Change, though, has also brought the Takacs renewal, adaptation, promise — and even, for the two current violinists, marriage.

Along the way, the Takacs that once carried forward the great Hungarian tradition of string quartets has morphed into something else, entirely its own. “It’s interesting,” Attacca Quartet violinist Amy Schroeder said admiringly, “because they have such a unique voice that I can’t really pinpoint whether it’s European, American, a combination of both or just the Takacs thing.”

The Takacs thing. “They have always been one of the world’s preeminent string quartets, and they have a unique approach to the repertoire,” said John Gilhooly, the director of Wigmore Hall in London. “Whatever they have, they have it in abundance.”

Ormai and Fejer were teenagers when they decided to form a quartet. In 1973, a year before they entered the fabled Franz Liszt Academy of Music in Budapest, Hungary, they asked Takacs-Nagy to be their first violinist, but they had to play trios for the two years it took them to find a second. Takacs-Nagy eventually found Schranz at a soccer match.

Hear Takacs-Nagy and Fejer talk about their education now, and it becomes obvious how lasting its imprint has been. Their teachers — Andras Mihaly, Ferenc Rados and, intriguingly, Gyorgy Kurtag — tried to instill a sense of musical morality in their students. “It was not aimed at chasing mistakes; they were looking for values,” Takacs-Nagy said. “We knew that behind every bar, every note, there are gold mines, diamond fields.”

Fejer recalled that they “thought we knew, if not everything, most things, and these three wonderful teachers made that confident feeling disappear in a matter of hours.”

Despite the travel difficulties imposed by life behind the Iron Curtain, the Takacs rose quickly, winning a series of competitions. They studied Bartok with Zoltan Szekely, who had premiered the composer’s Second Violin Concerto and still called his old friend Bela. They also found a mentor in Denes Koromzay, who, like Szekely, had played in the legendary Hungarian String Quartet. In time, Takacs-Nagy said, they became more aware of themselves as part of a distinguished national lineage.

“The Takacs offered all the virtues of Central Europe’s string-playing tradition and only occasionally its defects,” Bernard Holland of The New York Times wrote after hearing them on their first U.S. tour, in 1982. W

After a series of shorter stays in the United States, the Takacs members defected in 1986 and moved to Boulder, where Koromzay taught. The Hungarian String Quartet had once been in residence there, and the Takacs found a community proud to give personal and professional aid. One local philanthropist, Fay Shwayder, eventually bought it four new instruments; after Takacs-Nagy left the quartet with hand trouble in 1992, another benefactor offered Dusinberre a loan to buy a house.

The Takacs was already a fine quartet, with a lyrical, emotionally frank sensibility that rarely underplayed the character of a phrase. Soon after Dusinberre and Tapping joined Schranz and Fejer, though, critical admiration turned into critical adulation. In 1998, the Takacs released a set of visceral Bartok quartets on Decca that remains a reference today. Even more celebrated was a later Beethoven survey that New Yorker critic Alex Ross judged “the most richly expressive modern account of this titanic cycle.” Showered with awards, it showcased the kind of playing — daring yet secure, humane yet heaven-bound — that listeners could spend a lifetime with.

“If you look at our quartet, we’re clearly a multigenerational group,” Rhodes said. “We come from completely different cultures and backgrounds. I guess from my point of view, it would be weird if we weren’t representing that in some way.”