From a 1/4 tag: the center wave does a Swing and the very centers Cast
3/4 while the ends of the wave move forward. The outsides adjust to
make two stars, in the same way stars are formed on Explode the Top.
The stars turn 5/4 (yes, 5/4.) Then the people who find themselves in
the very center Cast 3/4 with each other, while the people behind them in
the stars move forward to become ends of the center wave. The others
adjust to become outsides of a 1/4 tag.