Group performs a dance together.
Some people are moving rhythmically together.
"Performs a dance" is a rephrasing of "moving rhythmically together".
exists e1 s1 x1 x2.(ne_org_group(x1) & a_together(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_perform(e1) & n_dance(x2))
exists e1 s1 s2 x1.(a_together(s2) & Manner(e1,s2) & a_rhythmically(s1) & Manner(e1,s1) & Actor(e1,x1) & v_move(e1) & n_people(x1))