Dear Ron, Yes, having a vertical line through the C tells us that the music is quicker, so that there are only two beats, not four: 2/4 instead of 4/4.
We sometimes refer to 2/4 as "alla breve" - to the breve. Alec Harman, in _Mediaeval and Early Renaissance Music_, Man and his Music, part 1 (London: Barrie & Jenkins, revised edn 1988) page 230, explains it as follows: "Composers could also quicken the speed of the tactus (they very rarely wished to slow it down) by means of 'proportional' signs, of which ¢ [C with a vertical line] was the most common. This was known as 'tactus alla breve' whereas C was 'tactus alla semibreve'. When ¢ occurs in a part previously governed by C, or is contrasted with other parts in C, then the breve tactus of the former is equal to the semibreve tactus of the latter and hence the semibreve in ¢ is performed twices as fast as in C." That seems easy enough, but Harman goes on to say: "On the other hand, from about Josquin's time on, ¢ more often means exactly the same as C!" Harman concurs with what Thomas Morley has to say about it on page 23 of _A Plaine and Easie Introduction to Practicall Musicke" (London, 1597): "_The signe of this Moode set with a stroke parting it thus ¢ [C with a vertical line through it] causeth the song before, which it is set, to be so song as a breefe or the value of a breefe in other notes, make but one ful stroke,_ and is proper to _motetes specially when the song is prickt in great notes._" In other words, C with a vertical line means that the beat or pulse is a breve, which would make the music buzz along quite quickly. However, Morley goes on to say that the same sign could mean that the beat was in semibreves, confirming that people used these signs in different ways: "Although that rule bee not so generally kept: but that the composers set the same signe before songs of the _semibriefe_ time .." On page 25 Morley describes how a vertical line through a mensuration sign will shorten the essential value of a note, meaning that you should take things quicker. He calls it diminution: "_Diminution is a certaine lessening or decreasing of the essential value of the notes and rests,_ by certayne signes or rules, by signes, when you finde a stroke cutting a whole circle or semicircle thus ..." He follows this with each of the four basic signs (a circle with a dot, a circle without a dot, a semicircle with a dot, and a semicircle without a dot) each with a vertical line going through. It's important to realise that it's not just the C sign which can have a vertical line. At this point in his book, things start getting complicated. There are signs with a cross instead of a vertical line, signs followed by numbers, the semicircle reversed (mirror image), and time signatures more as we have them today. It's no wonder there was a lot of confusion with regard to the use of these symbols, which is why Thomas Ravenscroft wrote his book, _A Briefe Discourse of the True Use of Charact'ring the Degrees_ (London, 1614), in an attempt to clarify it all. These mensuration signs serve two basic functions: 1) They tell us how notes are divided up, i.e. into twos or threes; 2) They tell us what the relationship is between two sections of a piece, i.e. how much faster or slower you go for a new section. As far as the Dalza piece is concerned, it is worth noting that each bar of the piece consists of one semibreve. In the first section we know from the mensuration sign (circle with a dot) that each semibreve is divided into three minims: | | | is the same as |\ |\ |\ | | | | | | We know from the half circle of the second mensuration sign that the semibreves thereafter are to be divided into two, not three any more. That means that | | | is going to be the same as |\ |\ | | | | According to Alec Harman, ¢3 (Dalza's second mensuration sign) means that three semibreves will occupy the same time as one semibreve in C. If this is what Dalza intended, three bars of the new section will occupy the time of two bars in the old section. The semibreve pulse indicated by the bar lines will be quicker after the second mensuration sign, but the speed of the crotchets will remain the same right the way through the piece. That's only my interpretation. I could well be wide of the mark. Further thoughts will be welcome. Best wishes, Stewart McCoy. ----- Original Message ----- From: "Ron Fletcher" <[EMAIL PROTECTED]> To: "'Stewart McCoy'" <[EMAIL PROTECTED]> Sent: Monday, November 06, 2006 9:24 AM Subject: RE: [LUTE] Dalza > Hi Stewart, > > Nice to see you back on the list again. > > So, C represents 4/4 time. But I have often seen C with a vertical line > through it... > > Does this mean exactly the same? > Or, does being bisected by a vertical line mean is it halved to 2/4? > > I have yet to spot the dots! > > Best Wishes > > Ron (down t' road) > > > 'Instead of a time signature of 4/4, we sometimes use C. That C is really > half a circle, not a letter C, and is one of the old signs of mesuration'. To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html
