The Short

294 TEMPO
In his discussion of 2/4, Schulz considered the theoretical relationship between the tempo terms, the tempo giusto of a
specific metre, and the note values, explaining:
It [2/4] is appropriate to all light and pleasant motions of feeling which, according to the quality of the expression,
can be softened by andante or adagio or made even more lively by vivace or allegro. The particular tempo of this
and all other metres is determined by these words and by the types of notes employed. 542
Schulz's reference to ‘the types of notes employed’ hints at a further subtlety in the system. The relationship between
larger note values and slower and heavier execution applied not only between metres with different denominators, but
also within the same metre. As has already been explained, a melody notated in 2/2 which was transcribed into half
note values in 2/4 would, assuming the tempo term remained constant, theoretically be performed somewhat more
quickly and more lightly; similarly, if a melody were renotated with halved note values in the same metre, so that two
bars of the original version became one of the new version, it too would be played faster and more lightly than before,
though not twice as fast. Only if the composer reduced the tempo term, say from ‘allegro con brio’ to ‘allegro
moderato’, would the music be played at the same speed. Such transference from one form of notation to another
within the same metre could take place without significant alteration of the pattern of accentuation, since tempo played
a large part in determining the frequency and weight of accents, though the different notation, even if the tempo
remained the same, would probably have been intended to convey a somewhat different message about the style of
performance. 543
For musicians responsive to these conventions, therefore, larger note values, even within the same metre, implied
slower and heavier music. An allegro in 2/4 containing a significant number of semiquavers as its fastest notes would,
therefore, probably have a crotchet pulse, and this would be faster and lighter than the minim pulse of one that
contained nothing faster than quavers. In that case the relationship that more commonly existed between pieces in
different metres would then exist between pieces in the same metre. 544 Thus, though the crotchet pulse of an allegro
containing semiquavers in 2/4 might be faster than the minim pulse of another having only quavers, the crotchets in
the latter would still be faster than the crotchets in the former. But as was normally the
542 In Sulzer, Allgemeine Theorie, 1st edn. ii. 1253.
543 See Ch. 16, ‘Heavy and Light Performance’.
544 The recognition of which note value constitutes the pulse unit in these instances depends entirely on the nature of the music. Quantz discussed a type of adagio 3/4 which
moves basically in crotchets and is performed at twice the speed of one in which there is quaver motion. A similar situation seems often to have existed with the true alla
breve; it is clear that ♩ was often used when ♭ was really meant, either because a composer regarded the value of the pulse unit as obvious or through inadvertent omission of
the vertical bar. The vexed question of alla breve is discussed more fully in Ch. 9 below.