Hello Charles, > I’m participating in the Google Summer of Code working on improving > LilyPond’s internal representation of chords.
As someone who uses chord names extensively, I’m thrilled that you’re tackling this! > The goal here is to create a data structure that will represent a chord’s > semantics beyond just a list of notes in the chord. Excellent goal! > it would be much better to maintain the information provided by the user in > chord mode about the semantics of the chord through to the naming process. Agreed. > Here is a rough list of semantic information I believe should be included in > the data structure: > root note > quality (major, minor, augmented, diminished) > extension (7, 9, 11, 13, etc.) > added notes (6, 9, etc.) > suspensions (sus4, sus2, etc.) > alterations (flat-5, sharp-9, etc.) > omitted notes > added bass note > inversions Yes. > Some things that should be thought about: > Is the 7 an extension? Or included in the quality the chord? Or maybe > something else? Since we’re starting from the ground up, can we not assume triadic harmony for the input (even if the output makes it look like we do)? For example, <c f bf> is not really, to my ears, a triadic chord with extensions and suspensions, but rather a quartic “triad”. Maybe there’s a way to handle this kind of thing (and others) elegantly? > How do we deal with semantics that may overlap between these categories? For > example: is a sharp-5 an alteration or just an augmented chord? A difficult question. Obviously, it would be great to allow the user — at the input, throughput, and output stages — to decide how to handle the information. > polytonal/stacked chords (like Cmaj / Bbmaj) Yes, please! > I would love to hear any ideas from the user community about this. And beyond > the specific issues I’m talking about here, what aspects of LilyPond’s > support for chords do you believe should be improved or changed? Here’s one off the top of my head: I would love to be able to easily input/output something like C /B /Bb I’d add more now, but I’ve got to go to see some new opera. =) > I hope many of you are excited about this conversation. I sure am! Please feel free to contact me on- or off-list with any questions. Best, Kieren. ________________________________ Kieren MacMillan, composer ‣ website: www.kierenmacmillan.info ‣ email: [email protected] _______________________________________________ lilypond-user mailing list [email protected] https://lists.gnu.org/mailman/listinfo/lilypond-user
