Tempo - Understood Tempo

Understood Tempo

In some cases (quite often up to the end of the Baroque period), conventions governing musical composition were so strong that no tempo had to be indicated. For example, the first movement of Bach's Brandenburg Concerto No. 3 has no tempo or mood indication whatsoever. To provide movement names, publishers of recordings resort to ad hoc measures, for instance marking the Brandenburg movement "Allegro", "(Allegro)", "(Without indication)", and so on.

In Renaissance music most music was understood to flow at a tempo defined by the tactus, roughly the rate of the human heartbeat. Which note value corresponded to the tactus was indicated by the mensural time signature.

Often a particular musical form or genre implies its own tempo, so no further explanation is placed in the score. Thus musicians expect a minuet to be performed at a fairly stately tempo, slower than a Viennese waltz; a Perpetuum Mobile to be quite fast, and so on. Genres can be used to imply tempos; thus Ludwig van Beethoven wrote "In tempo d'un Menuetto" over the first movement of his Piano Sonata Op. 54, although that movement is not a minuet. Popular music charts use terms such as "bossa nova", "ballad", and "Latin rock" in much the same way.

It is important to remember when interpreting these words that not only have tempos changed over historical time, and even in different places, but sometimes even the ordering of terms has changed. Thus a modern largo is slower than an adagio, but in the Baroque period it was faster.