timetempo

Timetempo refers to the relationship between time and tempo in musical contexts, particularly in music technology and performance practice. The term, when used, describes how tempo can be defined as a function of time or controlled by a tempo map that specifies tempo values at specific time stamps or bar boundaries. In this framework, tempo is not a single fixed value but a variable that evolves over the course of a piece.

In theory, timetempo is implemented via a tempo function T(t) in beats per minute, or via a sequence of tempo events that provide BPM values at given moments. Interpolation between events creates gradual accelerations or decelerations; abrupt changes can occur at event boundaries, yielding either smooth rubato or precise tempo shifts.

In practice, timetempo is central to tempo maps in digital audio workstations and notation software. A tempo track stores time-positioned tempo values; playback follows the tempo map, affecting timing of MIDI clocks and audio playback. The concept also supports time signature changes and alignment of performance with project tempo.

Applications include film scoring, electronic and dance music, and live performance, where expressive timing and pacing are important. In algorithmic composition, timetempo underpins tempo modulation and generative techniques that adapt tempo in response to musical events or external inputs.

Implementation notes: tempo values are typically expressed in BPM or microseconds per quarter note (MPQN). Standards and formats that relate to timetempo include MIDI setTempo events, MusicXML tempo indications, and DAW tempo ramps that interpolate between points linearly or nonlinearly. Tools vary in how they export and import tempo maps.

See also: Tempo, Tempo map, Rubato, MIDI, MusicXML, Digital audio workstation.