One of the highlights of “Musashi” — the Japanese play I reviewed in today’s paper — is the impromptu, tango-set dance that flows out of a sword-training session. Keep in mind that the show is set in a 17th-century Buddhist monastery, and you’ll get a faint idea of how deliciously surreal the scene is. Director Yukio Ninagawa incorporates the seeming anachronism to his advantage. It reminded me — in its spirit if not its letter — of the exhilarating finale of Takeshi Kitano’s 2003 samurai movie “Zatoichi.” Here it is, as a little Friday treat.