A woman is singing and playing the piano, at what appears to be a concert or event.
A woman is singing and playing the piano in a band.
Just because a woman is singing and playing the piano doesn't imply she is in a band.
exists e1 e2 x1 x2 x3.(n_piano(x3) & exists e3 p1 x4.(n_thing(x4) & at(e2,x4) & Topic(e3,p1) & Actor(e3,x4) & v_appear(e3) & exists p2 x5.((x4 = x5) & (n_concert(x5) | n_event(x5)))) & Theme(e2,x3) & Actor(e2,x2) & v_play(e2) & n_woman(x2) & Actor(e1,x1) & v_sing(e1) & n_woman(x1))
exists e1 e2 x1 x2 x3 x4.(n_piano(x3) & in(e2,x4) & n_band(x4) & Theme(e2,x3) & Actor(e2,x2) & v_play(e2) & n_woman(x2) & Actor(e1,x1) & v_sing(e1) & n_woman(x1))