« Back to Dictionary Index

A method of numbering musical compositions in the order of their publication, using the Latin word opus (work), appears first, though rather spasmodically, in the 17th century; it began to come into general use in the time of Mozart, but was not fully established until Beethoven’s time, the numbering not being carried out to all the published works of the former master.

No rule is observed as regards the size of an opus; for instance, Beethoven’s op. 1 consists of three pianoforte trios, while Schubert’s op. 1 is only the song ‘Erikonig.’

The opus number has nothing to do with the date of composition, but only with that of the publication; thus some early works, both of Schubert and Mendelssohn, were published (posthumously) with very late opus numbers.

Several mistakes have occurred in the numbering of Beethoven’s works in various editions; for instance, the three pianoforte sonatas (op.31) have often been called ‘op. 29,’ which is the number of the String Quintet in C, and the last four of the so-called ‘posthumous’ quartets have been numbered in two different ways.

The accurately chronological numbering is as follows:

  • The A minor Quartet should be op 130, not 132
  • That in B flat major, op. 131, not 130
  • That in C sharp minor, op. 132, not 131,
  • That in F major, op. 133, not 135

But it is unlikely that the series of more familiar, if less correct, numbers will now be abandoned.

« Back to Dictionary Index