Время создания: 1 августа 1826 года
Посвящено: Ignaz Anton Aloys Dembscher
Beethoven mostly wrote canons as a special, generally humorous form of communication with friends or acquaintances instead of or in letters.
Beethoven's String Quartet op. 130 was first performed by his friend Ignaz Schuppanzigh on 21 March 1826. Ignaz Dembscher, a rich music patron who was well-known in Vienna and an amateur cellist, was not present at the performance but let it be known that he could have the quartet performed at any time in a private concert with better artists. Even getting the music would not be a problem for him (Beethoven had in the past provided Dembscher with copies of several quartets). Beethoven had heard of this arrogant claim and been very annoyed by it. Shortly afterwards, when Dembscher had someone ask Beethoven for the quartet, the composer did not want him to let off so lightly. So he answered that he could gladly have the parts but would have to pay a fee of 50 florins to Schuppanzigh for borrowing them. Karl Holz passed on the composer's message and Dembscher replied with a sigh, "if it must be". Hearing this, Beethoven answered laughingly with the canon, "Es muss sein" ("It must be"). It can be dated to 1 August 1826 as an entry in a conversation book proves. In October 1826 Beethoven included the motto "Es muss sein" in the final movement of his last String Quartet op. 135.