Definition of "key-signature" [key-signature]

• In musical notation, the sharps or flats placed at the head of the staff to indicate the tonality of the piece and the black digitals to be used in performing it upon the keyboard. See key, 7 , and signature. (noun)

The Century Dictionary (Public Domain)

• "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."
• "_ -- 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."
• "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."