A COMPENDIUM, CONTAINING Exact RULES to be Observed in the COMPOSING of Two or more PARTS, Either for VOCAL or INSTRUMENTAL MUSIC.  
MUSIC is an Art of Expressing perfect Harmony, either by Voice or Instrument; which Harmony ariseth from well-taken Concord's and Discords.  
In the Scale there are Seven Notes, G, A, B, C, D, E, F, for their Eighths are the same in Nature of Sound.  
Of these Seven, some are called Concord's, and others Discords. The Concord's are Four in Number, viz. a Unison, a Third, a Fifth, and a Sixth.  
The Discords are Three in Number, viz. a Second, a Fourth, and a Seventh.  
The Third, Fifth, and Sixth are either Perfect, or Impefect. The Imperfect is less than the Perfect by half a Note: As,  
Unison. Imperfect 3d. Perfect 3d. Imperfect 5th. Perfect 5th. Imperfect 6th. Perfect 6th. Eighth. Second. Fourth. Seventh.  
In Composing of Two or more Parts, the Parts do either stand still. As,  
Or the one doth stand still, and the other move: As,  
Or they both ascend together: As,  
Or both descend together: As,  
Or one doth ascend and the other descend. As,  

The RULES following will direct how the Concord's are to be taken, or applied every one of these ways:  

RULE I.  
You may have as many Thirds, Fifths, Sixths, or Eighths as you please standing.   

RULE II.  
When one Part standeth still, and the other moves, the moving Part may move to any Concord's: As,   

RULE III.  
When Two or more Parts ascend or descend together, they ascend or descend either gradually, or by Intervals.  
If they ascend or descend gradually, they do move by Thirds, you may have as many Thirds as you please: As,  
Or ascend or descend by Sixths. As.  
Take no more than two or three Sixths; Or they move by a Fifth or a Sixth: As,  
You may have as many Notes as you p●ease.  
If two Parts ascend by Intervals, than you may move from  
A 1 to a 3 or 6  
A 3 to a 3 or 6  
A 5 to a 3 or 6  
A 6 to a 3 or 6   

RULE IU.  
If two Parts do descend together gradually, then as in the Third Rule: if by Intervals, you must move from  
A 1 to a 3 or 6  
A 3 to a 3 or 5 or 6  
A 5 to a 3 or 6  
A 6 to a 3 or 6   

RULE V  
If two Parts do move diversely, as one rising and the other descending: Then thus,  
Or thus,  
Or upon the Third, your Bass must begin in the Key, and end in the same Key.    

Of Taking Discords.  
Discords are either taken by way of Pass, or Binding.  

RULE I.  
Discords by way of Pass are taken thus:  
So thus you see, a Discord is placed between two Concord's.   

RULE II.  
A Discord is bound three several ways; first, between the Third, and some other Concord: As,  
The first Note of the upper Parts may be any Cord to the Bass, the second Note of the upper Part must be a Third to the Bass, the third Note must be a Second to the Bass, the last part of a third Note must be a Third to the Bass, and the closing or fourth Note must be a Third or Eighth to the Bass, as in the Example.  
The first Note of the Bass must be any Concord to the upper Part, the first part of the second Note of the Bass must be a Third to the second Note of the Triple or upper Part.  
The last part of the second Note of the Bass must be a Second to the upper Part, the Third Note of the Bass must be a Third to the second part of the third Note of the Triple, and Close as in the aforesaid Example.  
This Binding is seldom taken in a Close in more Parts than Two; but in the middle of a Lesson it is to be taken as often as you shall see occasion. This Binding is seldom or never taken in other Notes than in the Example.   

RULE III.  
The third way of taking a Discord by way of Binding is when the Fourth is taken between Second Thirds: As,  
So that you see the Discords is thus taken, viz. the first Note of the upper Part may be any Note to the Bass, the second Note of the upper Part must be a Fourth to the Bass, the eight Note of the upper Part must be a Third to the Bass, and the Close must be an Eighth or a Third, as in the Example.  
This Close may be used in any part of a Lesson of two or more Parts, either beginning, middle, or ending; but seldom it is to be omitted in the ending of a Lesson: This Close is seldom or never taken in longer or shorter Notes than in the Example.   

RULE IU.  
The fourth way of taking of a Discord by way of Binding, is when the Seventh is taken between the Sixth and Eighth: As,  
The first Note of the upper Part may be any Cord to the Bass, the first part of the second Note of the upper Part must be a Sixth to the Bass, the last part of the second Note of the upper Part must be a Seventh to the Bass, the fourth Note of the upper Part must be a Sixth to the Bass, and the Close must be an Eighth or a Third to the Bass.  
The Bass must descend four Notes, the two first Notes must be but half the quantity of the third Note, and the last Note as long or as short as you please.  
This Close is used in the middle strain of three or more Parts, and for the final Close many times of two Parts.  
To conclude; When you make one or more Parts to a Bass, you may begin your Bass in the Key, and end the Bass in the same Key. The middle (if you have more than two) may end in a Third, Fourth, and Fifth, from the Key. End your Lessons always with the Discord, according to the second Rule, that is, the Note before the Close must be a Fifth, if you fall to the Close, or a Foutth, if you rise to the Close. Your upper Part must begin in the Unison, Third, or Fifth, but not in a Sixth.    
FINIS.   

LONDON, Printed for William Gilbert at the Half-Moon in St. Paul ' s- Churchyard, 1673.