A singer in a white button-down shirt is performing while a girl plays the guitar in the back.
A young man and a young lady perform a concert.
The singer's gender and age are not revealed nor is the age of the guitar-playing girl. One cannot know it is a young man and young lady.
exists e1 p1 s1 s2 x1 x2 x4 x5.(n_back(x5) & n_guitar(x4) & exists e2 x3.(in(e2,x5) & Theme(e2,x4) & Actor(e2,x3) & v_play(e2) & n_girl(x3)) & while(e1,p1) & Actor(e1,x1) & v_perform(e1) & in(x1,x2) & n_shirt(x2) & a_button-down(s2) & Theme(s2,x2) & a_white(s1) & Theme(s1,x2) & n_singer(x1))
exists e1 s1 s2 x1 x2 x3 x4.(Theme(e1,x4) & Actor(e1,x1) & v_perform(e1) & n_concert(x4) & subset_of(x3,x1) & n_lady(x3) & a_young(s2) & Theme(s2,x3) & subset_of(x2,x1) & n_man(x2) & a_young(s1) & Theme(s1,x2))