A Philosophical Essay of Musick

As is evident by the note itself, it appears that any note may serve as the Key Note original: "Key Note"; the tonic or home note of a scale regarding its pitch. As for the species or types of keys, there are two: Flat and Sharp original: "Flat and Sharp"; referring here to Minor and Major keys.

When a tune begins with a flat third, it must continue that way; because the third is so closely related to the Key Note, it becomes joined with the memory of it and becomes, as it were, part of it. Introducing a sharp third would create a discord against that memory and disjoint the tune, even though a sharp third is technically a more consonant chord to the Key Note. It is necessary for the tune to proceed with regard to the preceding notes; for the same reason, once a sharp third is established, it must be maintained.

When the third is flat or sharp, the sixth must usually follow suit. Otherwise, the third—which is of principal importance and relation to the Key Note and sometimes features musical closures original: "closes"; cadences or points of rest—would have neither a perfect fourth above it nor a perfect fifth below it in the scale. Instead, it would have a false fifth original: "false fifth"; a diminished fifth or tritone, considered unstable and harsh, which could not present the note with the brilliance it ought to have.

There is no natural difference between music played in one Key Note or another; however, there are accidental differences. In some keys, the emphasized notes lie high and are more sprightly than in others. On some instruments, due to "holdings" sustained notes or open strings, the emphasized notes have a mellow and durable sound, which gives an advantage to that specific key. On most instruments, the emphasized notes are not perfectly in tune because of the "Schisms of Music" original: "Schismes of Musick"; the mathematical discrepancies in tuning systems like Just Intonation or Mean-tone temperament, which I will speak of shortly. Therefore, such keys are not commonly used, and when played upon, they yield a harsh tune. But these differences are merely accidental, relating to the advantages or imperfections of specific instruments.

I shall conclude from what has been said that the music of a single tune consists of the succeeding notes having a proper relation to those that came before. They must carry their proper emphasis through length, loudness, and repetition, with a variety that is pleasing to the hearer. This is called the "formality of a single part" the structural integrity or character of a single melodic line, an area where music is so abundant that it has provided every age and nation with a different fashion, and every musician with a particular style.