A quartet is performing inside.
Musicians are playing rock music.
A quartet can play music that is not necessarily rock music.
exists e1 s1 x1.(a_inside(s1) & Manner(e1,s1) & Actor(e1,x1) & v_perform(e1) & n_quartet(x1))
exists e1 x1 x2 x3.(ne_nam_musicians(x1) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_music(x2) & of(x2,x3) & n_rock(x3))