I have a couple of comments on jazz chords. This is stuff I have thought for a while,
but since this is currently being discussed
I thought I'd mention it.
Let's start here:
>The standard chord structure is the 7th chords. Examples:
>
>C-E-G-B would be notated as C triangle
>C-Eb-G-B =3D Cm triangle
>C-Eb-Gb-Bbb =3D Co (no "/7" as in the american chord style)
>C-Eb-Gb-Bb =3D C slashed o
>C-E-G-A =3D C6 (no "maj" as in the american chord style )
There isn't a standard for this. For example, I am a student at Berklee college of
music, where despite independent-thinking jazz
mentality there is a standard is because the faculty force one down students' throats.
(Don't ask me how they get themselves to
agree!) The colloquism here would disagree on the following points:
- maj is better than the triangle (I personally do like the triangle, esp for writing
things like C-(maj7))
- C maj/triangle should be reserved for C triad, adding a seventh if
one is desired. Also the default meaning for a letter alone is major triad. This is
not so imporant for folk/rock/whatever where
everything is a triad, but it is important in fusions styles where some chords are
triads and some aren't, and you want to have the
option of being explcit.
- ditto for minor and diminished triads. Add a 7th if desired.
- write half diminished as minor 7 b5 (I prefer the circle with the slash, no 7)
As for the issue of tensions (aka extensions - see there isn't even a standard name
for them) the Berklee convention does quite
well on everything from folk to progressive jazz, and the convention is:
- in a tonal jazz context, _do_ notate tensions if and only if they are _not_ diatonic
to the key signature. Notate them by any of
b9, 9, #9, 11, #11 b13, 13 inside parenthesis, usually stacked vertically and in
order. Special cases for sus4, #5, b5, "6", and
maj7 on minor triad which are all not considered tensions. Notating the tensions is
fairly important for tunes with tensions in
the melody (eg, Chelsea Bridge) and gets more important the more non-improvised parts
there are to the music. If a horn section in
a recording session is going to be playing natural 9 on a certain dominant 7 chord,
you want to give the piano player a chance to
play it right by telling him so so he doesn't choose #9 and clam.
- in either a folk/pop/rock (triadic) style or an atonal context, notate all tensions.
That said, I don't think anybody should go changing lilypond to compensate for the
Berklee system or any other for that matter, as
they won't mean anything if nobody uses them.
What I am confused about is why knowing what notes are in the chords is any of
lilypond's business. Yeah, it's kind of nice for
certain really simple styles for lilypond -m to bang out block chords in whole notes,
but considering asking a jazz pianist for F7
ususally results in something like
Eb - A - D - G - B
I don't know many jazz players/writers who really want to hear F A C Eb. I am doing a
jazz arrangement right now and the only way
I am keeping myself sane is to hand edit the score to take out the chord include line
before running -m. I did another project
where I just wrote the changes in as ugly text. Maybe there's some easier way but I
don't know it.
Basically, I think we should let lily just do notation. Do it right and handle the
things that it should, but doesn't (to my quite
limited knowledge- apologies if I am incorrect), such as:
G Fmaj7 / (b13)
--- / G F7 (#9 ) D-7 / / G7 | Cmaj
F7
^this by the way is the This is how to notate
more explicit symbol for rhythm when the melodic
the voicing above. The G staff is already used
means G major triad. for a different rhythm.
In extremely irregular
cases, "slash"
noteheads are specified
just for a measure
Typset the things as symbols, but don't even pretend to know voicings for chords,
unless there is a reason, like somebody thinks a
really cool hacking project is to get lilypond to look at the melody and chord symbols
and generate voicings for two hand piano
that fit, (and play in rhythm?) or else can analyze a score in notation and lossily
reverse construct the chord symbols or
something. (Incidentally, there is a whole subject called Berklee chord scale theory
that would make a nice framework.) IMHO
totally irrelevant for a music typsetting language, but whatever floats your boat.
Just draw the symbols and play silence in MIDI.
(Also make sure you have a reasonable way for getting the changes to appear only once
on the score but printed on every part.)
Basically, by assuming we know the notes ("voicings", as opposed to "chords") we are
just binding our hands to never really handle
jazz in an even semi-plausable way.
BTW jazzers- this is a tricky way to get something that looks like slashes on a staff.
Really stemless diamond noteheads on the C
space, but:
slash = \notes \transpose c' {
\property Voice.stemLength = #0
\property Thread.noteHeadStyle = "diamond"
c'4
\property Voice.stemLength = #7
\property Thread.noteHeadStyle = ""
}
of course this is for 4/4 on a treble clef. Gotta change it if you want dotted
quarter slashes on a 12/8 on a bass part or
whatever. By any chance, can anybody see a noninvasive way to hack this into the
fourth notation example by putting it up onto its
own invisible staff and maybe using (ugly but readable) regular text for chord symbols?
Jeff Henrikson
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