The traditional classical musical drama known as Noh has been performed on the polished floors of outdoor pavilions in Japan since the 14th century. San Francisco's Theatre of Yugen, now celebrating its 35th year, has drawn actors and musicians from Europe, Asia, and North America to practice the elaborately costumed form. To commemorate this anniversary, Theatre of Yugen is launching the first of four special events this season with "Getting to Noh Yugen" at NOHspace, Oct. 5-6. Activities include: A chance to try on the richly adorned costumes, an exhibition of Noh dances and their comic counterpart — the Kyogen dances traditionally seen during intermissions — and the performance of favorite scenes from past shows, including a not-so-traditional excerpt of their Frankenstein. Though "yugen" comes from the words "profound" and "dark," "Getting to Noh Yugen" promises a light introduction to a medieval form. The Oct. 5 show includes a preview of its upcoming season.