I asked this in the facebook group, but was rdirected to this mailing list, so... Here I am. :)
How can I print chordnames as roman numbers relative to given key? For instance, in key of C (given by \key c \major), I want the chord c:7 printed as I7 while in key of F, I want c:7 printed as V7.
Bonus:
I asked ChatGPT, and it suggested me to use the \degree command, with an example that looks really sane. The only problem is that there is no such command, but I will anyway show the example here, because it is just how I want it to work:
\version "2.22.1"
\score {
\new ChordNames {
\chordmode {
\degree
{c:maj}
{d:min}
{e:min}
{f:maj}
{g:maj}
{a:min}
{b:dim}
}
}
\layout { }
}
In this example, we use the \chordmode command to specify that we want to display chord names in roman numeral format. Then we use the \degree command to specify the degree of each chord relative to the key.
In this case, we're using the key of C major, so we specify the chords as follows:
c:maj represents a C major chord, which is the I chord in the key of C major.
d:min represents a D minor chord, which is the ii chord in the key of C major.
e:min represents an E minor chord, which is the iii chord in the key of C major.
f:maj represents an F major chord, which is the IV chord in the key of C major.
g:maj represents a G major chord, which is the V chord in the key of C major.
a:min represents an A minor chord, which is the vi chord in the key of C major.
b:dim represents a B diminished chord, which is the vii° chord in the key of C major.
When you compile this code in Lilypond, you'll get a score with the chord names displayed as roman numerals relative to the key of C major.