And age is an important component here, too, because post-9/11, many of those serving in particularly dangerous overseas posts are on the younger side.

"Country music, hard rock are more the themes than soundtracks. Music which pumps the blood up for mission or private pursuits like the gym," adds Richer.

"I don't know of an officer current or former who would define Justin Bieber or Taylor Swift as those they listen to. They do listen to Aerosmith, Coldplay and a lot of independent music artists."