Thank you David, that works perfectly. I would have probably never found this way, even if I understand what it does.
Sorry for the late response, didn't expect an answer that fast. If anyone is interested in this project, the full code as well as a quick-and-dirty documentation is available as a gist on GitHub: https://gist.github.com/TheNothingMan/6f5daf540d55b4ad9138e3ff5d3ffbd0 Thank you, kind regards! Am Di., 21. Jan. 2020 um 21:50 Uhr schrieb David Kastrup <d...@gnu.org>: > SK <s.skr.k...@googlemail.com> writes: > > > Hello, > > > > I wrote a script for generating music theory worksheets for school. One > > feature is the generation of chords that should be named by the students. > > The way this function works is by simply transposing some predefined > chords > > to a new randomly generated root. To keep the difficulty controllable, I > > would like to filter out double accidentals in some cases, e.g. to not > > produce an augmented F# chord. > > Does anybody know about a way to check in scheme if music has double > > accidentals, or can think of another smart way of doing this? > > > > I would not want to define all possible chords manually, and I think that > > filtering out certain root notes is quite complex, too, if you just want > to > > avoid double accidentals. > > > > Kind regards! > > #(define (has-doubles mus) > (any (lambda (p) (not (< -1 (ly:pitch-alteration p) 1))) > (music-pitches mus))) > > #(display (map has-doubles > (list #{ c'4 d' e' fis' g' a' b' #} > #{ cisis'4 d' e' #}))) > > -- > David Kastrup >
