How Fast Should It Go? The Words at the Top of the Page

The traditional vocabulary at the head of a score gives an instruction that is simultaneously about speed and about manner, which is why translations into plain numbers always lose something. The common terms run from very slow through moderate to very fast, and several of them originally described a mood rather than a rate, with one of the most common literally meaning cheerful and another meaning walking pace. That is not a historical curiosity, since a performer reading the cheerful marking is being told something about lightness and character that a number cannot convey, and two passages at identical speeds can be right and wrong respectively depending on that character. Additional words modify them, indicating a little more, a little less, very, or not too much, and further words describe articulation and feeling alongside the speed.

The core vocabulary runs roughly from slowest to fastest:

• •Grave and largo, very slow and broad
• •Adagio, slow and at ease
• •Andante, at a walking pace, which is the reference point for the others
• •Moderato, moderate
• •Allegro, fast and cheerful, which is the commonest marking of all
• •Vivace, lively, and presto, very fast
• •Prestissimo, as fast as can be managed

The metronome was patented in 1815 and composers began marking exact beats per minute, which looks like it should settle the question and does not. Beethoven supplied numbers for many works and a number of them are so fast that performers have argued for two centuries about whether his device was faulty, whether he meant something different by the notation, or whether the tradition has simply slowed down. Marks added by editors rather than composers are frequently mistaken for original. Composers have revised their own markings between editions and have given different numbers on different occasions. And a tempo that works in a dry small room is wrong in a large reverberant one, since the acoustics blur fast passages, which means a fixed number cannot be right everywhere. Performers therefore treat numbers as strong evidence rather than as instruction.

A single marking covers the piece, and the instructions for departing from it are a separate vocabulary worth knowing. Terms exist for gradually getting faster and gradually getting slower, for holding back momentarily, for a note or rest extended at the performer's discretion, and for returning to the original speed after a departure. Some traditions expect flexibility that is not written at all, with a soloist stretching and compressing the pulse against a steady accompaniment, which is a style-specific expectation rather than a universal licence. A slowing at the end of a movement is assumed in some periods and prohibited in others. Recordings from the early twentieth century reveal that performers of that era took liberties which later generations regarded as unacceptable and which are now being revived, so what counts as respecting the marking has itself moved considerably.

Experienced performers arrive at a tempo through considerations the marking does not state. The fastest passage in the piece sets a ceiling, since the whole must be playable, and choosing a speed that works for the opening and collapses later is a standard beginner's error. The harmonic rhythm, meaning how often the chords change, gives a sense of the underlying pulse that the surface notes can obscure. The acoustic of the room and the size of the ensemble both push slower as they grow. Historical evidence about the dance forms many pieces are based on constrains the possibilities, since a piece in the shape of a particular dance was played at the speed people danced it. And the instrument matters, since a passage that speaks clearly on one instrument becomes mud on another at the same speed.

The traditional words describe character as much as rate, with the commonest of them meaning cheerful and another meaning walking pace, which a number cannot convey. Metronome marks look precise and are disputed, with Beethoven's being argued over for two centuries. The fastest passage, the harmonic rhythm and the room acoustics all constrain what speed actually works.