Re: Chords and what they mean

[David Kastrup]

Noeck <address@hidden> writes:

> Hi LilyPond experts,
>
> this is a basic question that I have when I read this thread:
> How are chords stored and translated internally?
>
> From using LP, I know I can write in chordmode and in musicmode and I
> can get notes and chordnames:
> \chordmode  -> \new Staff
> \chordmode  -> \new ChordNames
> { }         -> \new Staff
> { }         -> \new ChordNames
>
> But I wonder: Does it always go through the music espression?

Yes.

> (1) \chordmode { c }  -> (2)  { <c e g> }  -> (3) ChordNames C
> It seems to be different as I can write:
>
> \version "2.19.21"
> music = { <b d' g'> \chordmode { g:/b } }
> \new ChordNames \music  % different names
> \new Staff \music       % same notes

The reason is that there are additional properties on the individual
notes in the chord expression recording some of their functional
relation to the \chordmode entry.  Try \displayMusic \music to see them.

> The core of my question is: Can the translation chordmode -> ChordName
> be defined independently of other translations. Must translations be
> bijective?

The translations are defined independently.  There is no convincing
amount of user-accessible documentation about how to trigger different
interpretations in a \ChordNames context when entering the music
manually, however.  So forcing particular interpretations of root note
and inversions factually requires entry using \chordmode.

-- 
David Kastrup