The use of the semibrevis is shown in the following chanson of Raoul de Coucy (1192): 

    [Illustration]
    [W:  Quant li rossignol jolis | chante
        Seur la flor d’este | que n’est la rose et le lis]

[G:  d’’ (c’’ a’) b-’ (a’ (g’ f’)) g’ (a’ b-’ a’ f’) f’ | f’ g’
a’ (b-’ a’) (c’’ d’’ c’’ b-’) (a’ g’) a’ |
d’’ (c’’ a’) b-’ a’ (g’ f’) g’ (a’ (b-’ a’) f’) f’]

The French troubadours and the German minnesingers of the thirteenth century used these forms of notes only, and even then restricted themselves to two kinds, either the longa and brevis, or brevis and semibrevis.

The necessity for rests very soon manifested itself, and the following signs were invented to correspond to the longa, brevis, and semibrevis [illustration].  Also the number of note symbols was increased by the maxima or double longa [illustration], and the minima [illustration], which represented half the value of the semibrevis.

Now that music began taking a more definite rhythmic form than before, a more regular dividing off of the phrases became necessary.  This was accomplished by the use of a dot, and another form, the perpendicular line, which we have noticed in the song of the King of Navarre (1250).  At first a means to indicate triple time was invented, and the measure corresponding to our [9/8] was indicated by placing the sign [O.] at the beginning of the line.  This was called perfect.  Then, for plain triple time the dot was omitted [O]; for [6/8] time the sign [C.] was adopted, and for ordinary common time [C] was taken.  Consequently, when these signs were placed at the beginning of the line they changed the value of the notes to correspond to the time marked.  Thus in [O.] (tempus perfectum, prolatio major) or [9/8], the brevis was reckoned worth three semibrevi [B = S S S] ([1. = 4. 4. 4.]); the semibrevis three minimi [S = M M M] ([4. = 8 8 8]).  In [O] or [3/4] time [B = S S S] ([2. = 4 4 4]); but the semibrevis was only as long as two minimi [S = M M] ([4 = 8 8]).  In [C.] or [6/8] time [B = S S] ([2. = 4. 4.]), but [S = M M M] ([4. = 8 8 8]).  In [C] or [2/2] time [B = S S] ([1 = 2 2]), and [S = M M] ([2 = 4 4]).

In the beginning of the fifteenth century the notes began to be written in an open form

[Illustration] Maxima. [Illustration] Longa. [Illustration] Brevis. [Illustration] Semibrevis. [Illustration] Minima. [Illustration] Semiminima, which was added later.

As still smaller units of value were added, the semiminima was replaced by [filled minima], and the half semiminima thus became [minima with tail], and the next smaller values, [two tails] and [three tails].  The rest to correspond to the semiminima was [illustration]; for the semibrevis [illustration], and minima [illustration].