Bay seniors ready for a break from all the season’s caroling might want to check out the evening of holiday flamenco at Pena Pachamama on Powell Street in the city. Castanets will starting snapping at 6:30 on December 28. Seniors $18. Come to think of it, this slow, sensuous style of dancing is perfect for seniors looking for a no-sweat exercise. There are plenty of classes available across the Bay Area.