Dear Maximilian and others, A few comments on the proposed patches for microtonal arrow notation. I've already noted these on the Google Code Issue dedicated to this topic: http://code.google.com/p/lilypond/issues/detail?id=694
... but obviously the -devel list is the place for serious discussion. My own starting point on this was the quarter-tone arrow example given in the NEWS section of LP 2.12: http://lilypond.org/doc/v2.12/Documentation/topdocs/cb/lily-a8064505.ly ... and I began a thread on the -user mailing list discussing my concerns and attempting to develop a solution: http://lists.gnu.org/archive/html/lilypond-user/2009-04/msg00139.html Briefly, the concern is this: that arrowed accidentals for quarter-tones (and indeed other microtonal intervals) introduce some new issues related to enharmonic equivalence. The note a quarter-sharp above A natural can be notated either A-natural-arrowup or A-sharp-arrowdown, and it may be desirable to use both within the same piece of music. Similar issues apply to quarter-flats. The existing solution in the NEWS section does not address this, permitting only one unique accidental for A-quarter-sharp. I don't think Maximilian's patches do either -- from what I can see they don't include natural-up or -down accidentals. I attempted to develop a solution to this with a slight cheat, by defining a very slight difference between quarter-sharp (+999/4000 instead of +1/4), which would be notated as a natural sign with an arrow up, and 'sharp-quarter-flat' (+1001/4000), which would be a sharp sign with an arrow down. A similar procedure was applied for quarter-flats. See: http://lists.gnu.org/archive/html/lilypond-user/2009-04/msg00649.html The problem with this approach was that it generated significant errors in transposition. It could not deal with the case when transposition suggested a pitch alteration of, say, +4999/4000, to say nothing of the case when pitches would be transposed by quarter-tones. (I have to say that the latter is a very tricky case anyway.) Beyond the need for natural-up and natural-down as well as sharp-up and sharp-down, my main concern for Maximilian's patches is that they will also run into transposition issues of this kind. Has this been tested for? A few more general comments. In response to Graham Percival's remarks, > Basically, I'm concerned about mixing the presentation and > definition (content) of pitches this closely. But I admit that > I'm not very familiar with this area, so I'll bow out of the > discussion now and let others comment. I think the key problem is that up- and down-arrows can mean different things in different musical contexts. The typical use is to indicate quarter-tones, but other composers have used them to indicate eighth-tones (e.g. Ferneyhough in several works, where arrows are applied not just to standard accidentals but also to the standard quarter-tone accidentals that Lilypond already supports). There are surely still other uses for arrow notation that I'm not familiar with. So with that in mind, it seems to me that the optimal approach is to have an up/down notation as the standard, and then let users redefine the pitch modifications (i.e. the values of SHARP-MICRO-UP etc.) as needed. This would mean the user could get the notation to mean what they want with a minimal level of fiddling. Probably it would be good if the default values were quarter-tones as this is the most common interpretation. Note that even with that implementation, users wanting a more content-oriented approach could define their own pitch notations (as I did in my patches) suitable to their approach. Lilypond could still include some switches, as you suggest, to define notations for various 'standard' approaches. Hope this email can lead to some productive development on Maximilian's patches as I am keen to see more extensive microtonal possibilities included in Lilypond. Best wishes, -- Joe _______________________________________________ lilypond-devel mailing list [email protected] http://lists.gnu.org/mailman/listinfo/lilypond-devel
