Laurie wrote:

>I note that you don't distinguish between Aeolian and minor - whereas I'd
>expect a piece in A minor to attract some E7 harmonies with  ^g leading
>notes - and indeed even ^f g^ double leading notes.

No, I only distinguished those modes which are used in the K: field of
abc.  Those tunes, as well as aeolian tunes will be reported as minor.
The object of the excercise is really to give the best entry for the K:
field.  I do do some further analysis to classify the gapped scales
which are related to the classical modes, and also to pick out a few
scales of which I have learned the names here (Freygish/Hejaz, Misheberach
etc.).  However, at the moment this is quite piecemeal.  Somewhere I have
a list of hundreds of named scales which I intend to convert to a computer-
searchable format so I can match them.

>As the score for ^g is 0.00 and the score for ^f is very small I presume you
>indeed did not have any such minor pieces in the sample set.

I guess so.  The data set used could certainly be improved on.  I would
like to have used ten times as many tunes, and many more of the rare
modes.

>It goes nicely with an "invent some guitar chords" algorithm.  I took the
>attitude that the user could enter "?" as a guitar chord and Muse2 would, on
>request, try to replace them with something sensible.  The chord chosen is
>given a score for
>*  matching the melody over the period until the next chord (the first
>melodic note is given extra weight - maybe eventually it should use stress
>patterns)
>* matching the key signature (i.e. not having out-of-key notes in it)
>* matching the chord before and the chord after (so that G=>A7=>D scores
>higher than G=>G#=>D)
>* random
>and you can set weights for deciding how important any of these are.  The
>weights can be negative, so if you really like dissonant, out-of-key chords
>in a jarring sequence you can have it.
>
>The chord before and the chord after could be further "?"s so in that case
>it looks for the "best" overall chord sequence.
>There is of course no such thing as "best", but anyway that's how it scores
>them.

Neat.  Nicely sidesteps the difficult problem of deciding where the chord
changes should be by placing the onus upon the user.

Phil Taylor


To subscribe/unsubscribe, point your browser to: http://www.tullochgorm.com/lists.html

Reply via email to