Beethoven’s last quartet was written in October 1826 at his brother’s country estate about 50 miles northeast of Vienna, where Beethoven and his nephew Karl had taken refuge after Karl’s attempted suicide. It was, needless to say, a difficult time, but the Quartet is such a congenial and fun-loving work that it is fashionable to regard it as a sort of regression to Beethoven’s 18th-century roots, which is a common misconception about almost any later Beethoven work that isn’t full of thunderbolts.

The scherzo is rife with rhythmic jokes likely to convince players that they are counting wrong, or that the composer is off his rocker. The four parts tug at each other in four different rhythms or get together to run up and down and stop for no good reason. In mid-movement, the first violin gets lost in a series of syncopated leaps while the three lower parts repeat the same five-note sequence 48 times.

Then the ridiculous gives way to the sublime: a placid, seamless slow movement consisting of three variations of a softly rolling theme.

Before the finale, a brief slow introduction followed by an energetic allegro, Beethoven wrote “Der schwer gefasste Entschluss” (the decision reached with difficulty, or the difficult resolution). Beneath it, he wrote the three-note motif of the slow introduction with the words “Muss es sein?” (Must it be?), followed by the two three-note motifs that make up the Allegro’s principal theme, underlaid with the words “Es muss sein! Es muss sein!” (It must be! It must be!).

This motto, preceding the final movement of Beethoven’s final quartet, has occasioned much speculation. Its roots seem to lie in a story about Ignaz Dembscher, who put on chamber music events in his Vienna house and normally attended the subscription concerts of the Schuppanzigh Quartet, which premiered Beethoven’s later quartets. Beethoven normally let Dembscher use his manuscripts in Dembscher’s house concerts, but when Dembscher asked for the score of the Opus 130 quartet after having not subscribed to the concert in which it was first played, Beethoven said no. Karl Holz, the second violinist in Schuppanzigh’s quartet, told Dembscher that if he wanted to use the manuscript he would have to pay the subscription price of the concert he’d missed. Dembscher asked, apparently with a smile, “Must it be?” As the story goes, when Holz told Beethoven about the conversation, Beethoven immediately wrote a canon for four voices to the words, “It must be! Yes, take out your wallet!” to a theme recognizably the same as the “Es muss sein!” theme of the Opus 135 finale.

Beethoven gave a different explanation in a letter telling his publisher Moritz Schlesinger that he was enclosing the last of the quartets Schlesinger was expecting: “Here, my dear friend, is my last quartet. It will be the last; and indeed it has given me much trouble. For I could not bring myself to compose the last movement. But as your letters were reminding me of it, in the end I decided to compose it. And that is the reason why I have written the motto “The decision taken with difficulty – Must it be? – It must be, it must be!”

For Beethoven, composition was a series of agonizing decisions about which version of a theme to use or which direction to take it, and it must sometimes have been an act of extreme will to make his choices and finish a movement. “Es muss sein!” may mean “At last, I know how it must sound.” Whatever the motto means, the note of triumph is unmistakable.

John Mangum is Artistic Administrator for the New York Philharmonic, having previously served in that position with the Los Angeles Philharmonic.