Musicians are sitting down and playing their instruments outside while people watch.
A string quartet practicing on the patio
Musicians are sitting down and playing their instruments outside while people watch does not imply they are a string quartet practicing on the patio
exists e3 e2 e1 p1 x1 x2 x3 x4 x5.(ne_nam_musicians(x1) & outside(e2,x2) & Theme(e3,x5) & Actor(e3,x4) & v_watch(e3) & (x2 = x5) & n_people(x4) & n_while(x2) & Theme(e2,x3) & Actor(e2,x1) & v_play(e2) & n_instrument(x3) & of(x3,x2) & n_thing(x2) & exists s1.(Theme(s1,x1) & a_down(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_sit(e1))
exists e1 x1 x2 x3 x4.(n_patio(x4) & a_topic(x1) & on(e1,x4) & Actor(e1,x3) & v_practice(e1) & (x1 = x3) & n_quartet(x1) & of(x1,x2) & n_string(x2))