Editing Non-traditional key signatures

The commonly used <code>\key</code> command sets the <code>keyAlterations</code> property, in the <code>Staff</code> context.

To create non-standard key signatures, set this property directly. The format of this command is a list:

 \set Staff.keyAlterations =
   #`(((<var>octave</var> . <var>step</var>) . <var>alter</var>) ((<var>octave</var> . <var>step</var>) . <var>alter</var>) ...)

where, for each element in the list, <var>octave</var> specifies the octave (0&nbsp;being the octave from middle&nbsp;C to the B above), <var>step</var> specifies the note within the octave (0&nbsp;means&nbsp;C and 6&nbsp;means&nbsp;B), and <var>alter</var> is one of <code>SHARP</code>, <code>FLAT</code>, <code>DOUBLE-SHARP</code>, etc., preceded by a comma.

Alternatively, you can use the more concise format <code>(<var>step</var> . <var>alter</var>)</code> for each item in the list if the same alterations are used in all octaves.

For microtonal scales where a “sharp” is not 100 cents, <var>alter</var> refers to the alteration as a proportion of a 200-cent whole tone.

<lilypond version="2.24">
\include "arabic.ly"

\relative do' {
  \set Staff.keyAlterations = #`((0 . ,SEMI-FLAT)
                                 (1 . ,SEMI-FLAT)
                                 (2 . ,FLAT)
                                 (5 . ,FLAT)
                                 (6 . ,SEMI-FLAT))
  % \set Staff.extraNatural = ##f
  re reb \dwn reb resd
  dod dob dosd \dwn dob |
  dobsb dodsd do do |
}
</lilypond>

[[Category:Contemporary notation]]
[[Category:Pitches]]
[[Category:Really cool]]
[[Category:Staff notation]]
[[Category:Included in the official documentation]]
[[Category:Snippet]]