Arsis and THESIS. (L.) Terms appropriated to prosody and melody. Arsis signifies the elevation of the hand, or that part of' the bar at which it is raised in beating time. Thesis, on the contrary, implies the fall of the hand, or that part of the bar. Thesis denotes the emphatic or accented part of the bar, and arsis the weak or unaccented part. Arsis and thesis, therefore, is but another expression for raising and falling, as applied to the action of beating time ; and is equivalent to accented and unaccented, as connected with the phraseology of the melody.
ARTEAGA, STEFFANO, a Spanish Jesuit, died at Paris in 1799. He wrote a work in three volumes, entitled "Le Revoluzioni del Teatro Musicale Italiano, dalla sua origin, sino al presente," the second edition of which appeared at Venice in 1785. He also wrote on the rhythm of the ancients, and was the most philosophical and profound of all authors upon the melo-drama.