What do you do in mission 9 tactical assassin 2

i havn't figured the whole thing out but i know that your supposed to shoot the top piece of wood on the tree to distract the first guard and the other guard is distracted if you shoot the electric box but i still haven't figured out the guy who is listening to music but i think you should shoot something on the music thing to get the guy distracted. Oh and by the way don't shoot the guy who is running he is the bomb guy.