Crispin Sexi (Jaysen Ollerenshaw), 2005
White mensural notation was used in Europe for the latter half of the 15thC and all of the 16thC for written music. 'White' refers to the fact that most of the note heads are not filled in, while 'mensural' refers to the fixed values of the notes in relation to each other. This notation is described by several period music theorists, including Tinctorus in the 15thC and Morely and Bathe in the 16thC. It is very close to modern notation, with the most notable differences being the diamond and oblong note heads, the rare use of barlines and the use of scary ligatures to sometimes combine groups of notes.
The note lengths used in White Mensural Notation are as follows:
A less obvious, but important difference between modern and Renaissance mensuration is that each Renaissance note length may be equal in duration to either three (perfect) or two (imperfect) of the next smallest note:
= = = = = = = = Crotchets and smaller notes are always divided by two.
The mensuration was indicated by the Renaissance version of a time signature, which specified the applicable combination of greater moode, lesser moode, time and prolation, as in the following examples:
The circle indicates perfect greater moode, the 2 is for imperfect lesser moode, the three is for perfect time, and the dot in the circle is for major prolation.
The broken circle is for imperfect greater moode, the 3 is for perfect lesser moode, the 2 is for imperfect time, and minor prolation is indicated by the missing dot.
Note that the full circle represents the Trinity, a perfect whole made up of three parts. The "C" therefore is imperfect, and indicates only two parts to a whole. The combination of O/C, two numbers and a dot gives for 16 different mensurations. These were usually abbreviated, leaving off one or both numbers. When one number was left off, the O (or C) specified perfect (or imperfect) for both the greater and lesser moode. When both numbers were omitted, the O (or C) indicated the time as well as the greater and lesser moode.
= 
= 
Sometimes, where abbreviated time signatures are used, the mensural ratio of the large to the long to the breve is indicated by the use of rests, and sometimes those ratios are assumed to be imperfect unless otherwise indicated, making for much confusion both then and now.
Here are the more common time signatures, including the note divisions:
: = , = , = , =
: = , = , = , =
: = , = , = , =
: = , = , = , =
: = , = , = , =
: = , = , = , =
Music theorists encouraged composers to alter their mensuration as often as seemed fit. This could be done within the space of a few notes. Different voices could also have different time signatures at the same time.
In addition to these time signatures, various methods are used to indicate tempo, including slashed time signatures (
and 
) known as diminution, which mean to play the piece twice as fast.
A change in tempo within a piece may be indicated by one number above another number (
). This means that the number of breves represented by the top number will now take as long to play as the number of breves at the bottom used to take.
Even allowing for changing the time signature as often as the composer likes, tricky situations still arise. To get out of trouble, the following devices could be used: a dot following a note extends it by the next shortest note; a dot above a note ("prick of division") can be used to indicate the previous note is extended, so that this note starts on a new beat; and the large, long and breve could all be drawn with black note heads to indicate they were worth two of the next smallest note, even in triple time.
The common time measures (being the number of counts per dance step) in Italian dance are Bassadanza, Quadernaria, Salterello and Piva. Joy and Jealousy assigns these the modern time signatures as follows:
or 
or sometimes Domenico felt that the difference of time between the four misure was 6:5:4:3. Commonly we use a ratio of 6:4:3:2 in order that all the note lengths keep the same duration while using the above time signatures, without need for a tempo change. Meanwhile, the dances transcribed in Joy and Jealousy show a variety of white mensural "time signatures" for the four misure. Looking at the original for Belregua, Fia Guielmina, Jupiter, Tesara, Sobria and Marcantia we get the following possibilities:
, , , , , 
Note that "C" is used in three different dance times; clearly the choice of moode, time, prolation and diminution is not straight-forward. Nor does the time signature necessarily change with a change of misure. Belfiore, for instance, combines quadernaria and piva in the same piece without any change of time signature in the original music. Fia Guielmina has sections of bassadanza in "C" and in "C-dot".
Why the variety? Unlike modern music, the time signatures used in white mensural notation do not dictate how many beats per measure. Rather they indicate the relationship between types of written note; how many semibreves per breve, how many minims per semibreve, and so on. The selection of a time signature is about the most elegant way to write the rhythm of the music without needing to resort too often to devices like dotted notes or pricks of division. A tenor line for bassadanza (in six) will show a preference for perfect time or prolation, whilst quadernaria (in four) will prefer imperfect time and prolation.
One final factor was that the acidity of the black ink was bad for the paper, and therefore using lots of black notes damaged the manuscript.
It must be noted that while Bathe's book agrees with the above definitions, Morley states that O on its own indicates imperfect greater and lesser moode. This might be a mistake in Morely's table showing the mensurations, since he otherwise confirms all other meanings above.
It is also possible that composers and musicians alike were in disagreement over exactly which sign meant what. In the mid 15thC, Tinctorus had the O or C always represent the time, and greater and lesser moode were indicated by use of a set of two or three Longa rests before the time signature. There are other interpretations and symbols used in time signatures, and in 1614, Ravenscroft published a book with the intention of sorting out the mess, once again having the O or C always be the time, but adding small numbers (33, 23 or 32) below it to show the greater and lesser moode. Where these two numbers are missing the musician is to assume the greater and lesser moode were imperfect.
While this new method adds to the set of possible interpretations, it would appear that several composers at least from England were happy with Ravenscroft's proposal. I leave you with the words of John Dowland, from the introduction to Ravenscroft's book:
Figurate Musicke doth in each Degree
Require it Notes, of severall Quantity;
By Perfect, or Imperfect Measure chang'd:
And that of More, or Lesse, whose Markes were rang'd
By Number, Circle, and Poynt: but various use
Of unskild Composers did induce
Confusion, which made muddy and obscure,
What first Invention fram'd most cleere, and pure.
These, (worthy Ravenscroft) are restrain'd by Thee
To one fixt Forme: and that approv'd by Me.
Bathe, William, A Briefe Introduction to the Skill of Song, c.1587, Kilkenny, Ireland, Boethius Press Limited, 1982.
Morely, Thomas, A Plaine and Easie Introduction to Practicall Musicke, London, Peter Short, 1597
Ravenscroft, Thomas, A Brief Discovrse Of the true (but neglected) vse of Charact'ring the Degrees by their Perfection, Inperfection, and Diminution in Measurable Musicke, against the Common Practise and Customs of these Times, London, Thomas Adams, 1614.
Stephens, Vivian & Cellio, Monica, Joy and Jealousy, Pittsburgh, PA, Real Soon Now Press, 1997.
Transcribing and Reading White Mensural Notation
http://ieee.uwaterloo.ca/praetzel/mp3-cd/info/raybro/index1.html
Accessed 19/6/2005
Mensuration - an introduction
http://anaigeon.free.fr/e_mensur_intro.html
Accessed 19/6/2005
Copyright Jaysen Ollerenshaw 2005. Free use for non-profit.
An earlier version of this artical also appeared in issue 27 of Cockatrice.
Joan & Crispin's Homepage: http://aelflaed.homemail.com.au/