Just seen some waltzing on TV (Andre Rieu). Some couples turned clockwise, others anti-clockwise. I am not a dancer. Is there any convention as to which way you turn when doing a waltz ?
no there isn't. before IIRC the 1920's couples just spun and spun in one direction all going one way around the floor and got dizzier and dizzier.
http://gregorious.hub.../Viennese-Waltz-Steps
In the 20's reversing came into general use but was considered rather "fast" as the man had to hold his partner more tightly to guide her into the reverse.