Re: Alternate chord: maj7 doesn't show up

[Noeck]

Hi Simon,

> \version "2.18.2"
> \chords { c/a }
> \chords { c:7/a:7 }

The »/« indicates that the lowest note (root) in the chord will follow,
e.g. c/a means <a c e g>
and you would usually use it for a note of the chord:
c/g = <g c e>
Therefore, the 7 does not make sense as it is a single note. This is
also explained here:
http://lilypond.org/doc/v2.18/Documentation/notation/chord-mode.html#extended-and-altered-chords

@bug: This information is missing here:
http://lilypond.org/doc/v2.18/Documentation/notation/common-chord-modifiers.html

And the :7 means a small seventh and not a maj seventh:
a:7 = <a cis e g>
a:maj7 = <a cis e gis>

I assume you want to have two chords to choose from at the same time.
I am afraid, I don't know how to do that. This is close, but you have to
place the chords on several points in time and if you use midi, you will
hear both for one quarter:

\chords {
  \set noChordSymbol = "/"
  c4:7 r a4:7
}
The / is produced by the rest (r). Usually the rest prints N.C. for no
chord.

Cheers,
Joram