I would say there are a few families of voicings worth knowing because of
the distinctive sounds they produce:
skeleton voicings
3/7 voicings
quartal voicings
polychord voicings
ad hoc voicings
"Skeleton voicings" are what Levine calls "Bud Powell voicings" - useful
primarily when playing tonal music in a solo or fast bebop group setting.
Hit the root plus the third and/or seventh, in root position. Simple and
effective.
3/7 voicings are what Levine calls "Bill Evans voicings" and Haerle calls
"category A/B voicings" - voicings contructed by using the third and
seventh plus whatever notes from the associated chord (including extensions
and/or alterations you choose). These make sense only with a bassist, but
work equally well with non-tonal / modal music as well.
Quartal voicings are built on fourths. They make most sense in modal
music, as they can establish a tonal center without reference to function.
Polychord voicings are simply rich sounding voicings, almost invariably for
dominant seventh chords, that are particularly easy to contruct reliably
(and each with a distinct and predicatable color).
Ad hoc voicings are voicings you play that are designed to convey the sound
of a chord while preserving either good voicing leading (assuming
relatively conventional harmonies) or perhaps a particular cluster density
you want to achieve or some other external criteria. Basically, you pick
the notes you want based on where your fingers are currently, your
knowledge of the chord and its function, and any other criteria.
For each category there are dozens of possible voicings. I do *NOT*
recommend practicing them exhaustively. I do recommend being able to find
the most basic couple of voicings of each category in each key, and being
able to figure out for yourself how you can vary them. Well, for polychord
voicings, there really are almost a dozen you might want to know the sound
of, but knowing them in one key should be good enough if you can think fast
enough to construct them in other keys on the fly. Of course, for ad hoc
voicings, you are on your own completely.
--------------
Marc Sabatella
marc@fortnet.org
http://www.fortnet.org/~marc/