noun
conductor's baton
Specifically the baton used by an orchestra conductor. The Japanese term 指揮棒 is a near synonym but タクト is more common in everyday speech.
from German Takt(stock)
See also: 指揮棒
指揮者がタクトを振り下ろすと、演奏が始まった。
When the conductor brought down the baton, the performance began.