ABSTRACT
Tempo implies a steadiness of beat, usually measured in beats per minute. During the baroque era, theorists still regarded it as the simplest form of measuring speed, but several other experimental methods were also devised. Tempo is affected by many factors, such as the size and acoustical characteristics of the hall, the particular instruments being used, and the size of the ensemble. The words adagio and allegro occur with some frequency in seventeenth century instrumental music, but other musical features may give a clearer guide as to the appropriate tempo. At least three types of adagio are frequently encountered in the eighteenth century: a middle movement marked adagio consisting usually of an imperfect half-cadence with some elaboration, either written out or implied; adagio marked at the end of a movement to mean ritardando, or "slower than the prevailing tempo;' and a complete movement whose spirit must be determined from the meter, key, dissonance, and harmonic rhythm.
