A lone musician in black is on stage, playing an acoustic guitar and singing into a microphone.
A lone musician playing for an audience.
The fact that the musician is on stage playing an acoustic guitar and singing in front of a microphone implies that he is playing for none other than audience.
exists e1 e2 p1 s1 s2 x1 x2 x3 x4.(for(p1,e2) & into(e2,x4) & n_microphone(x4) & Actor(e2,x1) & v_sing(e2) & for(p1,e1) & Theme(e1,x3) & Actor(e1,x1) & v_play(e1) & n_guitar(x3) & a_acoustic(s2) & Theme(s2,x3) & exists x5.(on(x1,x5) & n_stage(x5)) & in(x1,x2) & n_black(x2) & n_musician(x1) & a_lone(s1) & Theme(s1,x1))
exists s1 x1 x2 x3.(a_topic(x1) & for(x1,x3) & n_audience(x3) & n_playing(x1) & of(x1,x2) & n_musician(x2) & a_lone(s1) & Theme(s1,x1))