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relation between beat, duration, and BPM

Antescofo
#1

Hello all,

Apologies if this has been covered elsewhere (I’m sure it has, but where? I
can’t find it I’m afraid):

I’m writing an asco score file generator for my algorithmic composition
software (http://www.michael-edwards.org/sc) and need to clarify something
about durations. I understand durations are expressed as fractions/multiples of
a beat; I also surmise that there’s no concept of meter, as such, in antescofo.

So I’m just wondering how I should handle compound meters. I’m guessing that
e.g. in 6/8 time the BPM would be entered as e.g. 120 or something (where we’d
mean dotted quarter = 120, though antescofo doesn’t need to know our beat
type), and then each 1/8 note would be an antescofo duration of 0.33, just as
if it were a triplet in 2/4 time. Is that right?

Best, Michael

#2

Michael,

All event durations are expressed in beat units in Antescofo. We don’t have any notion of Time Signature and as a consequence, we don’t have explicit Bars or Measures but it is easy to get around it. We chose this in the very beginning of Antescofo with Marco Stroppa (@marco) so that scores are as general as possible.

If you have compound Time Signatures, it is easy to derive the Beat Unit out of it! For example: In a 3:4 Time Signature, the beat unit is obviously a Quarter-Note (crotchet). In 6:8, as you mention, a beat unit is equivalent to an eighth-note (quaver). Note that in BOTH cases, an event with a duration of one beat-unit has an Antescofo duration of “1.0”! Typically when you change Time Signatures, in Antescofo you should change your Beat-Unit (for conversion) and Tempo accordingly. That’s all!

Note that fractions (such as Triplets) can be expressed either as floats (like 0.33) or fractions (like 1/3).

However: If you and other users have further suggestions on this, we’d be very happy to integrate in the language! I just haven’t thought up to now that it’d be overkill… . So any suggestions would be welcome.

#3

Thanks Arshia. No, no further suggestions. I think the original thinking was bang on. I just needed clarification because with my slippery-chicken algorithmic composition hat on an 1/8 note has a value of 0.5 whether in 6/8 or 3/4. So I just needed to put on a new antescofo hat to understand that it’s now 0.333 in 6/8 and 0.5 in 3/4. Perfect. I’ve tested this with my current piece and it’s working just fine.

Cheers, Michael