Phil Taylor wrote: > > John Walsh wrote: > > > Which brings up a thought: this list would be a good forum for > >developers to publish algorithms and little bits of code of which they're > >particularly proud---or maybe just links to them. Then other developers > >could use it, and, out of politeness, put in acknowledgements to the > >effect that "the following is X's algorithm to do Y" in their own code > >when they do. The mode-guessing algorithm is one example, Phil Taylor's > >alternate intonation is another. This could help speed up development in > >general, and possibly even reduce the number of alternate solutions---and > >divergent development---in abc programs. (This isn't as radical as > >open-source development: it doesn't require organization, just two basics > >of human nature: pride and laziness.) > > Here's a description of the key/mode algorithm which I wrote for Bruce some > time ago. The actual code wouldn't be much use to anyone here, since it's > inextricably mixed in with the rest of BarFly, and it's written in Pascal > anyway. >
> > Phil Taylor > > To subscribe/unsubscribe, point your browser to: >http://www.tullochgorm.com/lists.html I must admit that I didn't use it, because I don't think that a statistical approach is needed here. [I did actually program that data collection into my ABC player program, but didn't have the patience to run through a large number of tunes in a variety of modes and collect the results. And are you using tune modes or scoring modes?] Also Phrygian and Lydian are rather uncommon (and Locrian useless) and there are a substantial number of non-'Greek' modes that are much more common (see table below).] The mode of the tune is determined by the keynote and the notes in the tune, and may or may not have anything to do with the scoring mode specified in K:key-mode. A program to find keynotes for such would appear to me to be more useful. [My ABC player program determines scoring mode from the final note and sharps or flats on the key signature, but final mode is the tune mode, not the scoring mode, and that comes from notes in the tune, and of course, isn't necessarily a 7 note 'Greek' mode, and in a slight majority of cases it is not.] Correct me if I'm wrong, but it seems to me the key is the 'final' note of the tune (96% of those I've stressed note coded), except in cases of circular modes and questions only arise in connection with keynotes for circular modes (4% of those I've stresssed note coded). [This is not strictly true, but exceptions are rare. A variable 2nd strain can lead to different modes for tunes whose 1st strains are identical. e.g., in 'Sources of Irish Traditional Music', prototypes #456 ("And the Kirk Woud Let Me Be") and #738 ("Silly Old Man"), are both versions of the Scots 'Fye let us a' to the Bridal'(#377). An obvious difficulty with stressed note coding, one I haven't yet solved, is that the keynote comes from the end of the tune, while the stressed note code is for the beginning of the tune.] Let us realize that putting sharps or flats on the key signature is purely for convenience, so we don't have to place them on the affected notes throughout the tune. Obviously, that doesn't affect the mode of the tune, but, unfortunately, it usually changes the scoring mode (all except for those with no sharps or flats on the key signature). That's one more reason why I'd like to see the key-mode in K: eliminated; we can cut out ambiguity in notation and put in into interpretation where it belongs. How well does the 7 note 'Greek' mode model serve us? Mode distribution: Highest 31 modes (of 179) of the 6601 tunes stressed coded in file Comcode.TXT on my website. Letters x= a to g are the keynotes for which modes have no sharps or flats. In xn, note n of the scale is missing. v = variable, vm is variable mth note of scale (natural plus sharp or flat depending on scoring mode). mode scale # of some descriptions notes tunes 1 ionian 7 2038 2 cv7 8 534 ionian with 7b added 3 ion/mix 6 425 no 7th 4 aeolian 7 403 5 lyd/ion 6 365 no 4th 6 mixolydian 7 327 7 dorian 7 301 8 dor/aeol 6 288 no 6th 9 av7 8 166 natural 7 added to aeolian 10 c(or f)v4 8 142 4th nat. and sharp 11 c6 6 120 ionian missing 6th 12 melodic min. 9 115 13 g(or d)3 6 102 no 3rd 14 pi1 5 100 15 d(or a)v6 6 82 6th natural and flat 16 aeol/phry 6 76 17 dv7 8 67 7th flat and natural 18 d(or a)6v7 7 63 no 6th, 7th nat. and flat 19 g(or d)v3 8 46 20 cv5 8 38 21a pi3 5 35 21b c(or g)v47 9 35 23 pi4 5 34 24 c(or g)67 5 33 25 cv1 8 30 26 lydian 7 29 27 phrygian 7 28 28 c(or g)3v7 7 26 29a c(or g)4v7 7 23 missing 4th, 7th natural and flat 29b c3 6 23 ionian minus 3rd 31 harm. min 7 21 aeolian 7b sharpened to 7th natural Note how often it's the 7th or the 6th that gets changed a bit from that of the normal for a 'Greek' mode to make a common non- 'Greek' mode. I was a bit surprised that aeolian was down to 4th place. I suspect it would be higher in a selection of more modern tunes. For the 652 traditional Irish vocal melodies collected in the early 20th century that are coded in Huntington and Hermmann's 'Sam Henry's Songs of the People' the order is: ionian, ion/mix, lyd/ion, pi1, pi4, mix, dor/aeol, aeolian, mix/dor, dor, aeol/phr. Of the most common 7 modes here, only ionian has as many as 7 notes, and aeolian is down to 8th place. The 'Greek' mode model starts out with a bang on ionian, but after that doesn't match very well with what's observed. I don't, think, however, that the 'Greek' mode model is going to disappear in the near future; it's just too hard to figure out anything else. Homer got it wrong; it should be "Beware of Greeks bearing modes". Bruce Olson -- Roots of Folk: Old British Isles popular and folk songs, tunes, broadside ballads at my website <A href="http://www.erols.com/olsonw";> Click </a> Motto: Keep at it; muddling through always works. To subscribe/unsubscribe, point your browser to: http://www.tullochgorm.com/lists.html
