Visible crew/equipment: Before we see Chef with his Bunny, the camera pans along from the rear of the helicopter to the front. First we see the reflected studio lights, then we see a great reflection of a cameraman with his equipment under a hood in the window of the copter. (01:27:50)
Visible crew/equipment: If you keep your eyes on the right side of the screen before Colonel Kilgore gives the injured VC soldier a drink you can see a crew member's hand holding a light meter pass quickly in and out of the shot. (00:29:20)
Visible crew/equipment: The boom mike reflection can be seen in the pilot's side window of the helicopter as Captain Willard walks up to Kilgore. (00:26:55)
Visible crew/equipment: After a soldier hands Colonel Kilgore the Air-Cav shorts that he gives to Lance, the reflection of several crew members can be seen moving in the middle of the megaphone to the right of the screen. (00:48:40)
Visible crew/equipment: As they get the boat ready to head for shore if you look closely at the left the screen turbulence from the engines of the camera boat can be seen in the water as it passes them. (00:24:45)
Visible crew/equipment: The boom mike, camera and lights can be seen in Lieutenant Kilgore's sunglasses as he gets out of his helicopter. (00:27:05)
Visible crew/equipment: After Clean is killed in the rocket attack there are several shots where the camera crew films the front of the PBR as it approaches them. The spray and turbulence from their boat in front of the PBR can be seen in all of these shots. (01:52:20)
Answer: It's not any specific song; it's just the kind of generic piano music you'd hear at dinner at a high-class restaurant of the era. Think of scenes in movies, films, etc. set or made in the '50s and '60s, where the characters go to a nice dinner and there's someone at the piano playing unobtrusive music to accompany the food/conversation.