A guitar band is playing on stage.
There are musicians are performing music.
Performing and playing are synonyms in band speak.
exists e1 x1 x2 x3.(on(e1,x3) & n_stage(x3) & Actor(e1,x1) & v_play(e1) & n_band(x1) & of(x1,x2) & n_guitar(x2))
exists e1 p1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_perform(e1) & n_music(x3) & exists x4.((x2 = x4) & n_musician(x4)) & (x1 = x2))