The autobeam filter can be used to automatically add beams to notes according to the prevailing meter. Here is an example where the autobeam filter is being applied to the music, which contains one measure of 3/4 music and another in 6/8.
Try deleting the filter from the above Humdrum data and see what happens.
In the VHV editor, you can also type alt-c to “compile” the filter, which will result in the beam markers being added to the data in the editor. (The alt-c command will not work on this page, however).
Selecting a particular spine
If only a single staff needs to be processed, then used the -t (track) option.
The first track (spine) is the left-most (beginning) one in the data. Here is an
example of beaming the second track (spine) while leaving the first one unaltered:
Selecting a particular staff
In addition to selecting by track, you can also select by staff.
Specifically by **kern spine number, starting with 1 as the lowest
staff (left-mote **kern spine in the data). In the following data,
the last spine is the 3rd track, but the 2nd staff:
Removing beams
Use the -r option to remove existing beams. Here is an example
where the beams on the top staff are removed:
Splitting beams by lyrics
The -l option can be used to break beams so that lyric syllables
start at the beginning of beam groups. In the following example, the
top staff shows the original beaming, and the bottom staff show the
beaming after being processed with the autobeam -l filter. This splits
the second beat’s beam into two groups: a single eighth note with is underneath,
and the syllable so- starting a new beam group of two notes from the rest
of the beat.
Note the filter extract -s 1-$,1-$ which duplicates the original system
of music. Then the -k 1 option for autobeam applies beam breaking for syllable
starts only to the first kern spine (the lowest staff in the system).