A beat is the basic unit of time and has no other meaning than that. It is not hard-wired to any musical note.
What consists a beat is defined in the tempo marking of a piece.
Example:
This means that one dotted quarter note is considered to be the beat and it fits 50 times in a minute.
THE NITPICK:
Reaper considers a beat as always being a quarter note. Example:
- Set BPM to 120 and the time signature to 4/4 and listen to the metronome
- Now change the time signature to 8/8 and listen again. The metronome doubled in speed.
Since there is no setting that defines what musical note is a beat, one would expect that the denominator of the time signature would be the beat. So, no matter if the time signature is 8/8 or 4/4, one would expect that the metronome would beat at the same speed.
PROPOSAL:
Add a setting where the user can define the musical note of a beat. In order to be backwards compatible with existing projects, if it is not set (overridden) by the user then Reaper assumes it is a quarter note (as it has been doing for all this time).