People are listening to their headphones as they hold on for a ride on public transit.
People are bobbing their head's listening to music.
The people may be motionless and not bobbing their heads.
exists e1 p1 x1 x2.(exists e2 s1 s2 x3 x4.(for(e2,x3) & on(x3,x4) & n_transit(x4) & a_public(s2) & Theme(s2,x4) & n_ride(x3) & a_on(s1) & Manner(e2,s1) & Actor(e2,x1) & v_hold(e2)) & n_thing(x1) & n_thing(x1) & as(e1,p1) & to(e1,x2) & n_headphone(x2) & of(x2,x1) & Actor(e1,x1) & v_listen(e1) & n_people(x1))
exists e1 x1 x2 x3 x4.(to(e1,x4) & n_music(x4) & Theme(e1,x3) & Actor(e1,x1) & v_bob(e1) & n_listening(x3) & of(x3,x2) & n_head(x2) & of(x2,x1) & n_thing(x1) & n_people(x1))