What is the elevation of the hand, or that part of the bar at which it is raised, in beating time; the weak or unaccented part of the bar; - - opposed to thesis. Moore called?

arsis — (Mus.) The elevation of the hand, or that part of the bar at which it is raised, in beating time; the weak or unaccented part of the bar; - - opposed to thesis. Moore. (Webster's 1913.)

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