Time point
- 3 min read
- 2 chapters
Related on Lably
Through Music, Point (geometry) and Time
Interonset interval
Half time: the snare moves to beats 3 of measure one and two (beats 3 & 7) while the hi-hat plays only on the quarter notes. Also, the quarter notes 'sound like' eighth notes in one giant measure.
The corresponding term used in acoustics and audio engineering to describe the initiation of a sound is onset, and the interonset interval or IOI is the time between the beginnings or attack points of successive events or notes, the interval between onsets, not including the duration of the events. A variant of this term is interval of onset.
For example, two sixteenth notes separated by dotted eighth rest, would have the same interonset interval as between a quarter note and a sixteenth note:
The concept is often useful for considering rhythms and meters.
Sign in to keep reading
One more chapter is free with a Lably account.
Time-point sets
In serial music a time-point set, proposed in 1962 by Milton Babbitt, is a temporal order of pitches in a tone row which indicates the instants at which the notes start. This has certain advantages over a duration scale or row built from multiples of a unit, derived from Olivier Messiaen.
since duration is a measure of distance between time points, as interval is a measure of distance between pitch points, we begin by interpreting interval as duration. Then, pitch number is interpretable as the point of initiation of a temporal event, that is, as a time-point number.
— Milton Babbitt
For example, a measure may be divided into twelve metrical positions. In 3
4 this equals sixteenth notes. The start of each position, or time point, may then be labeled, in order, 0–11. Pitches may then be assigned locations within measures according to their pitch set number, now their pitch/time-set number. In Babbitt's first example he shows subsequent numbers which ascend (0–11) as within the same measure (if four follows three it may sound immediately), and subsequent numbers which descend as in the following measure (if three follows four it must necessarily wait for the next appearance of time-point three).
Babbitt uses time points in Partitions (1957), All Set (1957), and Post-Partitions (1966), as well as in Phonemena (1969–70), String Quartets No. 3 (1969–70) and No. 4 (1970), Arie da capo (1974), My Ends Are My Beginnings (1978), and Paraphrases (1979).
Charles Wuorinen has also developed an approach to the time-point system, which differs greatly from Babbitt's.