In that Lacour etude, he uses the double sharp as part of downward sequence. And the double-sharp clearly helps the performer visualize the contour of the sequence.
Thanks again for posting that. It seems to me it’s actually a perfect example of a reason someone may want to employ a double.
Sorry, what? Yes, they are relatively rare but that doesn’t mean “hardly anyone has used them for the past 500 years”.
Also, the fact that you don’t encounter many double accidentals in Messiaen is because he chose one spelling for his modes and then stuck to it, even when they don’t always make the most melodic sense. Lots of diminished 3rds and 4ths for example, and a lot of mixing of flats and sharps in close proximity. Of course, that’s not generally the kind of stuff one sight-reads in a studio either…
Sorry, what? Lots of people use them? I think your words, “relatively rare”, and my words “hardly any of the people and scores….employ them” are synonymous. ; ) WHen you quote you gotta get the words right.
I think Messiaen made sense, he’s just a few levels above us. It’s possible you’re not grasping his spelling because he’s thinking about things that are more grand and poetic than a melodic line. Who knows.
But, aside from, G# major etc, where would you use them?