Re: Chords in LilyPond

[Kieren MacMillan]

Hi Matthew (et al.),

> Request for "rootless slash chords”

> the user will enter something like
>  \chordmode { c c/e c/g }
> to get the desired output of
>  C /E /G

Definitely on my wish list.

> with LilyPond doing some kind of translation to not show roots when there's
> a slash, but what would make sense would be for the user to enter
>  \chordtext { c /e /g }
> and get
>  C /E /G
> That would be easy by directly printing the input with only formatting
> translations (I am counting the lowercase to uppercase conversion as
> formatting) and much harder with an attempt to go to notes and back in
> between.

Why, exactly?

   input: c c/e c/g

   throughput, step 1:  <c e g> <e g c> <g c e>
   throughput, step 2: “Oh! They’re the same chords consecutively, just in 
different inversions! Let me check what the user prefers for output…”
   throughput, step 3: “They’ve selected ‘rootless slash chords for two or more 
consecutive rootless chords’ and ‘all caps’.”

   output: C /E /G

Where precisely is the problem that arises in that translation to notes?

> it sure would be easier to just type
>  \chordtext { G7alt }

Definitely on my wish list.

> We cannot expect to translate it to notes cleanly without
> more information about what it means

Agreed. But that’s easy to set up via preferences, settings, context 
properties, etc.

> but we don't need to know what it means to engrave it.

More accurately/explicitly: we don’t need to know what the symbol “G7alt” means 
in order to engrave *the symbol*.
But to engrave (or manipulate, etc.) *the chord*, we definitely *do* have to 
know what it means.

> User wants to enter:
>  \chordmode { e13 }
> and get
>  E13

Same example as above.

> User wants to engrave a chord they describe as "Gm7(b5)/F" and is told to
> type
>  g : m7.5- / f
> Note the desired output does not contain a colon or hyphen.  Using that
> suggestion, as in
>  \new ChordNames { \chordmode { g : m7.5- / f } }
> will actually engrave
>  Gø/F
> (where the ø is superscript).  User doesn't pursue it further, but this
> output does not closely resemble the requested
>  Gm7(b5)/F

That’s merely a default/stylesheet issue.
(Note: I’ve long argued for a set of chord-exception stylesheets that go beyond 
the one that’s included out of the box.)

> Counterpoint:  "but MIDI!" is a common argument for
> why chords ought to always have translations to notes.

Although I don’t currently use MIDI much, I think this is a great argument for 
chord translation.

> if we care so much about MIDI, why can't we have better MIDI support

“Patches are gratefully accepted.”

> if LilyPond is not about MIDI, chord names should not be about MIDI either.

That’s a logical fallacy. (Actually, a combination of at least two.)

Cheers,
Kieren.
________________________________

Kieren MacMillan, composer
‣ website: www.kierenmacmillan.info
‣ email: address@hidden