key-signature

“The same key-signature may stand for either one of two keys, the major key, or its relative minor, hence in order to determine in what key a melody is one must note whether the tones are grouped about the major tonic DO or the minor tonic LA.”

Music Notation and Terminology

“_ -- The student is advised to recite the _harmonic form_ of the minor scale as was suggested in the case of the major scale, noting that the "raised seventh" does not affect the key-signature.”

Music Notation and Terminology

“G-clef and F-clef; construction of major scale (without key-signature), note-values, and rhythm (different rhythms with the same meter), normal, harmonic, and melodic minor scales (without key-signatures); key-signatures; notation of chromatic scale with each key-signature; intervals; definitions of terms most frequently used in music.”

University of Virginia Record

“Purcell frequently set a double bar at the end of a section, and makes two or more numbers where a modern composer would simply change the tempo and key-signature and go straight on, so that the scrappiness is only apparent.”

Purcell