A Fourth

THis, of all Consonances, is the most unhappy; nor is it ever used in Tunes, unless by Accident, and with the assistance of others: not that it is more imperfect than a Third Minor, or a Sixth, but that it approacheth the nature of a Fifth so neerly, that the grace of this is drowned in the sweetnesse of that. To the understanding of which, we are to note, that a Fifth is never heard in Musick, but that, in some sort, an acuter Fourth is withall advertised…

[Diagram showing lines AB, DB, and EF representing string lengths/proportions]

…whence it comes, that it may be called the shadow of a Fifth, which perpetually accompanies it; and thence also it is evident, why a Fourth cannot be set in Tunes, primarily, and per se, i. e. betwixt a Basse and another part… a Fourth would bee most harsh and unpleasant thereto, as if only the shadow were presented instead of the body, or the Image objected instead of the Thing it selfe. (Page 21) Of MUSICK. (Page 25)

…the chiefest Variety doth arise from these four last; whereof a Ditone and Sixth Major are more gratefull, more sprightfull, and exhilarating than a Third and Sixth Minor; as hath been observed by Practicall Musicians, and may be easily deduced from hence, that a Third Minor is generated from a Ditone only by Accident, but a Sixth Major per se, because it is no other but a Ditone Compound.

This, of all Consonances, is the most unhappy.

Nor is it ever used in Tunes, unless by Accident, and with the assistance of others: not that it is more imperfect than a Third Minor, or a Sixth, but that it approacheth the nature of a Fifth so neerly, that the grace of this is drowned in the sweetness of that.

To the understanding of which, we are to note, that a Fifth is never heard in Musick, but that, in some sort, an acuter Fourth is withall advertised; which follows from what we have sayd [30], that in an Unison, there is, in some sort, resounded an acuter Eighth.

For example, let AC be in distance form DB of I [image of a diagram with lines and points A,C,D,B,E,F] dne the resonance thereof, more Acute by an Eighth, be EF; and certainly that will be distant from DB, by one Fourth: whence it comes, that it may be called the shadow of a Fifth, which perpetually accompanies it; and thence also it is evident, why a Fourth cannot be set in Tunes, primarily, and per se, i. e. betwixt a Basse and another part. For when we sayd, that other Consonances were necessary in Musick, only in order to the variation of a Fifth; certainly, it is evident, that a Fourth would be useless, in regard it cannot vary a Fifth: which appears from hence; that, if it were set in a more Grave part, it would alway be resound more Acute than a Fifth, where the Hearing would soon perceive that it is disturbed from its proper place to an inferiour one, and so a Fourth would bee most harsh and unpleasant thereto, as if only the shadow were presented instead of the body, or the Image objected instead of the Thing itself.