Metronome marking
Tempo indication in beats per minute, related to a note value.
What it means
A metronome marking fixes the tempo as a number: it names a note value and the number of its beats per minute. The notation ♩ = 72 thus means 72 quarter notes in one minute. Unlike tempo words such as andante or allegro, which designate a range and a character, the metronome marking is unambiguously measurable.
The reference note value is thereby just as important as the number. The same music can be marked with ♩ = 120 or with an indication on the half note, and the two mean different things. In alla breve and compound metres, the marking often refers to the dotted quarter or the half note, that is, to the actually felt beat.
Metronome markings are to be read with caution. Many do not come from the composer but from the editor; others are transmitted but disputed, because they seem unusually fast or slow. As a guideline they are almost always useful, as a prescription rarely.
In the notation
The marking stands above the staff, usually to the left of or below the tempo word, in the form “note value = number.” Range indications such as ♩ = 60–66 occur. In many editions, brackets indicate that the marking was added by the editor — a note that can be confirmed in the preface. At tempo changes, the new marking stands at the point concerned.
Musical use
Since the early nineteenth century, with the spread of the metronome, such numbers supplement the traditional tempo words. In twentieth-century music they often become the main indication, especially where tempo changes are to be exactly determined. In older music they are absent and, where they appear in editions, are always an addition by the editors.
Performance practice
Check the reference note value first, before setting the metronome — this is where most misunderstandings arise. Use the number for orientation and for checking, not as constant accompaniment; a piece practised only to the metronome loses its phrasing. Practise difficult passages first more slowly and increase in steps. And check whether the marking fits the character: if it seems impossible, a look in the preface at who it comes from is worthwhile.