I usually prefer the 8va extension lines to end at the end of the note duration, and not up to the last note symbol. Is there a way to make this the default behavior, or set it in the Properties pane, without having to edit each of them in Engrave mode?
If you want a workaround that will track with note spacing changes, you could put a small value hidden note in another voice at the end of the bar. A bit more involved than moving the end point graphically but it won’t need to be adjusted if the spacing changes.
My opinion: The longer extension may seem more logical, but it doesn’t convey any different information, and is a little harder to read since your eye has to track back and forth a bit to match the end with the last note. These examples all being handwritten are unconvincing to me in terms of editing for publication.
If music scores were linear representations of sound in time, this would be necessary.
E. Gould says that the practice of continuing octave signs for the value of a long note is found in “some editions” but considers it to be incorrect, which it clearly is since it is needless clutter. That some composer do it is probably due to ignorance of standard engraving practice. Were there a trill and squiggle for the value of the note, however, she recommends it.
This case may explain why the cited composers prefer to extend the 8va sign to the end of the note duration: because it communicates the same sense of duration as a trill squiggle.
While looking around for examples of 8va I’ve noticed that nearly all the classical literature have it in conjunction with passages of short-duration notes. The difference in the end position of the squiggle is not very noticeable in this case.
Music during the 20th Century has gone more toward a sense of flow, and notes have often became longer. In the examples the 8va squiggle would look uneven, if extending for the full length of the first notes, but not over the last one of the sequence. It would be as if one of the graphic elements of the score didn’t go at the same pace as the others.
From the players’ perspective the 8ve continuation line is wholly redundant on long tied notes and just clutters space. Once the note is sounded they only need to be informed of changes (dynamic/ technique etc.)
To my mind the continuation line is only of interest to the composer/score reader.
This triggers an interesting consideration for me (not an engraver, but a composer trying to do my best with engraving) – maybe a better way to notate 8va would be writing the 8va symbol, and then just a hint of the continuation line, eventually fading away. A little like a laissez vibrer notation.
Looking at your 3 examples: The Ligeti 8ve mark and line are redundant (for the player) as it is tied from earlier (I would just notate where the 8ve terminates). The Koechlin is essential as the pitches change. But for both that and the Stockhausen I would just terminate the continuation line after the note, not the bar end.
The appearance of the music, the mental comprehension of it, and the physical sensation of playing are one unit to an experienced player. The continuation line sets off an area in which the notes have a different meaning than usual , and omitting it would be disconcerting to the player. It is for this reason the lines have been used since the very beginning of the use of octave signs.