In the Old Tradition* tempo was indicated both by the time signatures and the shortest or fastest notes in a piece of music. Italian terms, such as Allegro, Presto, Adagio, etc., were used sparingly and had no more than a complementary meaning. Their function was to remove the limitations imposed by the time signatures and they were employed as indications of character, rather than as directions as to tempo. When, at the beginning of the 18th century, the new Style Galant evolved, Italian terms came to be used to indicate the tempo of a piece in conjunction with time signatures and actual note-content. A clear description of this system is given by Johann Philipp Kirnberger in his book Die Kunst des reinen Satzes in der Musik (Vol. II, 1776, p. 107--"Von der Bewegung") where he explains the term Tempo giusto:
"Tempo giusto is determined by the time signature and by the longest or the shortest note values contained in piece. Once a young composer has grasped this fact he will soon understand to what extent the added terms Largo, Adagio, Andante, Allegro and Presto with their qualifications such as Larghetto, Andantino, Allegretto, Prestissimo will increase or reduce the speed or slowness of the natural flow of pace. . . ."
Of the many authors who wrote about the new approach to tempo, two, Joachim Quantz and Friedrich Wilhelm Marpurg, exercised great and lasting influence.
Though in many respects still leaning towards the Old Tradition, Quantz's ideas of tempo were progressive, and he developed in his book Versuch einer Anweisung die Flöte traversière zu spielen, 1752, the first workable method for measuring pace. He did this by means of the human pulse, estimating eighty pulse beats to the minute--which is equivalent to ≩ = 80 on our metronome. Quantz distinguishes between two principal kinds of pace only, a fast and a slow one and not, as was done by later authors, between a slow, a moderate and a fast one. Quantz subdivides each of the two kinds of pace into two groups and thus establishes a system of four groups of pace: a very fast and a moderately fast group and a slow and a very slow group. What is strange in this arrangement is the omission of a fast group between the____________________