An interesting way to build intensity in a score is to employ a musical tactic called Tempo Modulation. Tempo Modulation (TM) is defined as a change of tempo by pivoting on a common durational unit (Benadon 2004, p. 563). By taking the time value of a subdivision in one tempo and then finding a corresponding tempo that has the same time value for one of it’s own subdivisions, a relationship between two tempi is established that is useful in transitioning from one to the other without losing the listeners’ sense of pulse/beat.
For example, at 80 bpm an eighth note triplet has a duration of 250 milliseconds (ms) which is the same duration of an eight note at 120 bpm. Emphasizing the eighth note triplet subdivision at 80 bpm and then by treating that note value as an eighth note in 120 bpm, a tempo change can smoothly be made which will increase the activity/tension/drama of the music and effectively support the building dramatic arc of a scene in a cohesive way.
references:
Benadon, F. “TOWARDS A THEORY OF TEMPO MODULATION”. Proceedings of the 8th International Conference on Music perception & Cognition, 563-566, 2004.
Pounding Pangea is a cinematic percussion track that uses this technique. At :28 the triplet is introduced. The break down from :41 to 1:01 still references the old tempo but in 6/8 meter. At 1:08 the modulation is complete and the piece is in a new tempo and meter.
Horrific Surge is another cinematic percussion/sound design track that uses a similar approach. Although the tempo doesn’t technically modulate there are shifts of meter and feel that are accomplished by analogous “pivoting” methods.
