a group of man are sitting outside playing music.
A jam session is taking place in the park.
Even though they are playing music, it may not be a "jam session." And just because they are outside, they aren't necessarily in the park.
exists e1 x1 x2 x3 x4.(outside(e1,x3) & n_music(x3) & of(x3,x4) & n_playing(x4) & Actor(e1,x1) & v_sit(e1) & of(x1,x2) & n_man(x2) & n_group(x1))
exists e1 x1 x2 x3 x4.(n_park(x4) & in(e1,x4) & Theme(e1,x3) & Actor(e1,x1) & v_take(e1) & n_place(x3) & n_session(x1) & of(x1,x2) & n_jam(x2))