Re: Help with Auto-beaming rules

[N. Andrew Walsh]

I've seen contemporary scores that follow the following basic rules:

All notes within the pulse value (say, a quarter-note in 4/4) are beamed into one group. If the total group has values shorter than a 16th (this includes 16th-note tuplets) then only the first beam carries across the whole group, and all other beams are broken at the 8th-note. In the OP's example, this would mean four groups of 32nd notes under one single beam, but the 2nd and 3rd beams subdivided.

This seems a reasonable approach, but I sometimes have trouble getting Lily to do it without using overrides. Is there a simple rule I could put at the top of the file that would do this?

Cheers,

A

On Tue, Sep 8, 2015 at 1:58 PM, Simon Albrecht <address@hidden> wrote:

Hello Richard,

Am 08.09.2015 um 13:43 schrieb Richard Shann:

The attached bit of 18th century typesetting shows an 8.[ 32 32] beamed
group and a series of  32[ 32 32  32] beamed groups in a 2/4 time
signature. This is quite typical of the period and is IMHO more legible
than if the 1/32 notes were beamed in larger groups.

Of course.

Can this be done by auto-beaming rules in LilyPond?
My attempt follows - I have created two bars beamed manually and
followed with two bars which I hope to auto-beam by feeding the first
two bars to  \beamExceptions.
8>< 8>< 8>< 8>< 8>< 8>< 8>< 8>< 8>< 8>< 8>< 8>< 8>< 8>< 8>< 8>< 8>< 8><

\version "2.19.5"
MvmntIVoiceI = {
          e''8.[ fis''32 g''] e''8.[ fis''32 g'']
          c'32[ d'32 e' f'] c'32[ d'32 e' f'] c'32[ d'32 e' f'] c'32[ d'32 e' f']
          c'32 d' e' f' c' d' e' f' c' d' e' f' c' d' e' f'
          e''8.( fis''32 g'') e''8.( fis''32 g'')

}
\layout {
     \overrideTimeSignatureSettings 2/4 1/4 #'(1 1) \beamExceptions { 8.[ 32 32] 8.[ 32 32] |

OK, the problem is that the NR doesn’t describe the limitations set for using \beamExceptions. One exception can always only use one duration, not different ones. This is because internally \beamExceptions creates a Scheme nested list of the type used in scm/time-signature-settings.scm, where each ‘exception rule’ is of the form ((1/32 . (4 4 4 4))). And there’s no way of translating { 8.[ 32 32] 8.[ 32 32] } into such a rule.

Be that as it may, I would like to be sure that this beaming cannot be
done with a single \overrideTimeSignatureSettings at the outermost
context, that is, that individual passages will need to be marked to
achieve the desired beaming.

Yes, this will require manual beaming.

Yours, Simon

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