This is a vocabulary for precisely describing a position in time and the passage of time itself, in both real and musical terms.
In addition to real time (e.g. seconds), two units of time are used:
frames
and beats
. A frame is a numbered quantum of time. Frame
time is related to real-time by the frame rate
or sample rate
,
framesPerSecond. A beat is a single pulse of musical time. Beat time is
related to real-time by the tempo
, beatsPerMinute.
Musical time additionally has a meter
which describes passage of time
in terms of musical bars
. A bar is a higher level grouping of beats.
The meter describes how many beats are in one bar.
Index
Classes
Rate
Class| Label | Rate |
|---|---|
| Subclass of | Position |
| In domain of | beatUnit |
| beatsPerBar | |
| beatsPerMinute | |
| framesPerSecond | |
| speed |
The rate of passage of time in terms of one unit with respect to another.
Properties
barBeat
Propertybeat
Property| Label | beat |
|---|---|
| Domain | Time |
| Range | xsd:double |
| Type | Datatype Property |
The global running beat number. This is not the beat within a bar like barBeat, but relative to the same origin as time:bar and monotonically increases unless the transport is repositioned.
beatUnit
Property| Label | beat unit |
|---|---|
| Domain | Rate |
| Range | xsd:nonNegativeInteger |
| Type | Datatype Property |
Beat unit, the note value that counts as one beat. This is the bottom number in a time signature: 2 for half note, 4 for quarter note, and so on.
beatsPerBar
PropertybeatsPerMinute
Propertyframe
PropertyframesPerSecond
PropertyHistory
- Version 1.6 (2019-02-03)
- Clarify time:beat origin.
- Version 1.4 (2016-07-31)
- Define LV2_TIME_PREFIX.
- Version 1.2 (2012-10-14)
- Use consistent label style.
- Version 1.0 (2012-04-17)
- Initial release.
A point in time and/or the speed at which time is passing. A position is both a point and a speed, which precisely defines a time within a timeline.