A musician with long hair performs on a stringed instrument.
The instrument might be a guitar
Stringed instrument doesn't imply guitar.
exists e1 s1 s2 x1 x2 x3.(on(e1,x3) & n_instrument(x3) & a_stringed(s2) & Theme(s2,x3) & Actor(e1,x1) & v_perform(e1) & with(x1,x2) & n_hair(x2) & a_long(s1) & Theme(s1,x2) & n_musician(x1))
exists e1 p1 x1.(n_instrument(x1) & exists p2 x2.((x1 = x2) & n_guitar(x2)) & Topic(e1,p1) & Actor(e1,x1) & v_might(e1))