To find out what's happening in St. Moritz, check the weekly Engadin Information brochure (it has an English section), available at the tourist office, hotels, and shops.
There are organ concerts in Arosa's Bergkirchli (mountain chapel) from Christmas through mid-April and in summer, Tuesday at 5. The town's alphorn and yodeling festival takes place in July. Check with the tourist office for information on either of these events.