TEMPO (It., time). The degree of rapidity with which a piece of music is to be executed. The rhythmical proportions of notes, as indicated by their form, give them only a relative value, and have no reference to the absolute speed at which the entire composition is to be played. The varying rates of speed at which different compositions, or portions of compositions, are to be played is usually indicated by certain terms called tempo marks. These terms are not, how ever, always used with exact precision, and some times apply more to the character than to the absolute speed of performance. The following table gives the most usual tempo marks with their approximate significances: The tempo is indicated with far greater ex actness by references to the beats of the metro nome (q.v.). It is not, however, uncommon for composers to express the tempo by reference to some well-known musical form which has a char acteristic movement. as 'tempo di mareia,' 'tempo di value,' tempo di minuetto,' etc. Schumann and Wagner discarded the Italian nomenclature and indicated the tempo by means of German terms. In this they have been followed by a few other composers, but the German terms are not well enough known to be free from a certain vague ness. The Italian terms came into use at the be
ginning of the seventeenth century. Before that time the means of expressing the general speed at which a composition was to be played were very limited. In uninsurable music (q.v.) each note had a certain average time value (integer valor) ; but in the course of years the unit of measure changed so frequently that great con fusion ensued. In transcribing works of the six teenth century in modern notation all notes must, as a rule, be reduced to about half their face values; while in still older works the reduc tion should be to a quarter or an eighth of the original value. Tempo rubato (stolen time) is the name given to a mode of performance to which a restless character is imparted by pro tracting one note beyond its proper duration, and curtailing another so that the aggregate duration of each measure remains unchanged. Mortifica tion of tempo is a term first used by Richard Wagner, in his article "Veber das to indicate that a composition cannot be played throughout in strict metronome time. This is especially true in dramatic music, and throws the responsibility for the interpretation of the music upon the conductor