This is a vocabulary for describing a position in time and the speed of time passage, in both real and musical terms.
In addition to real time (based on 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, time:framesPerSecond. A beat is a single pulse of musical time. Beat time is related to real-time by the tempo, time: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.
The rate of passage of time in terms of one unit with respect to another.
Properties
barBeat
Property| Label | beat within bar |
|---|---|
| Domain | Time |
| Range | xsd:float |
| Type | Datatype Property |
The beat number within the bar, from 0 to time:beatsPerBar.
beat
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 time: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 |
The note value that counts as one beat.
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
Propertyspeed
Property| Label | speed |
|---|---|
| Domain | Rate |
| Range | xsd:float |
| Type | Datatype Property |
The rate of the progress of time as a fraction of normal speed.
The rate of the progress of time as a fraction of normal speed. For example, a rate of 0.0 is stopped, 1.0 is rolling at normal speed, 0.5 is rolling at half speed, -1.0 is reverse, and so on.
History
- 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 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.