Grace note documentation

[davidrizo]

Please, when possible it would be very useful to have documentation about grace notes. I've found the ones related to cue-sized notes, but not that for appoggiatura and acciaccatura.

At least it would be nice to know what part of the explanation about it in https://www.humdrum.org/rep/kern/ is supported in VHV. I've tested the encoding of acciaccaturas with q and it works, but not the appoggiatura with P and p, or the grace note groups.

Thanks.

[craigsapp]

Yes, there are difference between the official documentation and implementation in VHV (which I will fix sometime...).

The short answer is that in VHV "q" is an acciaccatura, and "qq" is an appoggiatura, and "Q" is not used (but I may remap it to cue-sized notes). "P" and "p" are qualifiers on appogiatura notes.

Here are some examples of each case:

The first measure is an acciaccatura, the second is an appogiatura. To be more precise, the "q" means that the note is a grace note, and that the grace note has a slash on it. The "qq" marker means that the note is a grace note and it does not have a slash. So "q" and "qq" are focused on notational aspects of the grace notes. There are certain styles of music notation where acciaccaturas are given without a slash, so "qq" does not guarantee an appogiatura, only that "qq" likely means an appogiatura based on common graphical representation of appogiaturas.

To be more explicit for appogiaturas, a "P" should be added to the grace note as shown in measure 3, and then a "p" on the following note. Measure 4 shows the grace note converted into a regular note in a performance rendering of the grace note. The modern style is to display most appogiaturas in measure 4 format, where the original 18th-century edition would have used the measure 3 format.

In other words "q" and "qq" are graphical descriptions, and "P"/"p" are analytic descriptions.