Key signatures are the fast way to indicate flat and sharp notes for an entire melody. Keys can be Major or Minor and exist for every note in the 12 tone scale.
In a multiline song, indicate key signatures with a
line, like this:
play """ K: Db DEFGABC'D' """
In the key of D flat major, every D, E, G, A and B is flat.
Names of key signatures are written using
b (lowercase b) for flat
# (shift-3) for sharp. This is different from the way
sharps and flats are written for individual notes in a melody.
In the key of D sharp minor, every D, E, F, G, A, and C is sharp.
play """ K: D# minor DEFGABC'D' """
Notice how the scale has a very different character when written in a different key signature.
Individual accidentals can be added to the key signature by
listing the notes with
^ for sharp and
_ for flat.
For example, the harmonic D# minor key adds a double-C-sharp to the melodic D# minor scale. It can be written like this:
play """ K: D# minor ^^C DEFGABC'D' """