The key signature indicates the tonality in which a piece is played. It
is denoted by a set of alterations (flats or sharps) at the start of the
staff.
Setting or changing the key signature is done with the \key
command
\key
pitch type
Here, type should be \major
or \minor
to get
pitch-major or pitch-minor, respectively. You may also
use the standard mode names (also called “church modes”): \ionian
,
\locrian
, \aeolian
, \mixolydian
, \lydian
,
\phrygian
, and \dorian
.
This command sets the context property
Staff.keySignature
. Non-standard key signatures
can be specified by setting this property directly.
Accidentals and key signatures often confuse new users, because
unaltered notes get natural signs depending on the key signature.