Nah, something's not right, I popped the disc in and there's music on every one of those tracks.
Tracks 14,15,16 & 19 aren't more than about 10 seconds in duration, but they do have short music passages (probably end of mission/"you died" types of quickie music, haven't had time to play it yet). The others range from roughly 2.5 to 6 minutes.