Single File Revolve to a Wave can be done from
any 1x4 Column. The Center of the 1x4 Column acts as
either the Lead Belle or Trailing Beau (depending upon facing
direction) since these dancers reach the center of the 4-dancer
formation first. Similarly, the End of the 1x4 acts as either
the Lead Beau or the Trailing Belle.
Centers end as Centers, and Ends end as Ends of a R-H Wave.
More information on 'Single File' can be found at
http://www.ceder.net/def/singlefilec3.php