"He's the one who likes all our pretty songs
and he likes to sing along
and he likes to shoot his guns
but he knows not what it means
Don't know what it means."
- Nirvana "In bloom"
That lyric comes from a song which sounds cheery and as dictated was sung along loudly when the band played it live, the majority of audience completely overlooking the irony of it all.
I guess it goes back to children's songs like "Rings around the Rosie" which is about the black plague and has been sung cheerfully by children who have no concept of the topic they're singing about. And it has been something which has been used over and over in popular music, a song that sounds really happy and everybody sings it along, not really realizing what that song is actually saying.
Buck Owens "Act Naturally" is a good example, the subject of the song is somebody who isn't really worth all that much in daily life and is cast for a movie where he basically has to be himself: a miserable piece of crap. http://www.youtube.com/watch?v=fOpgL4mqEis
Blur's "Country house" sounds really festive, even having a marching band in it. But lyric-wise it's about a guy who has achieved all his goals in life he set out to achieve and basically has no idea on what to do next and sits alone in his huge mansion withering away because of boredom. The "Blow, blow me out I am so sad I don't know why" lyric in the background from the second chorus on shows that the subject is on the brink of suicide. http://www.youtube.com/watch?v=gpuh1WE-RVw
Sometimes, the fact that people sing along with a song but having no idea what the song is about gets that song in a place where it shouldn't be. That happened when Ronald Reagan decided Bruce Springsteen's "Born in the USA" should be his campaign song. Reagan probably never even looked at the lyric sheet to find out that this epic song was NOT the "Proud to have been born an American" he mistakenly made it out to be. http://www.youtube.com/watch?v=7oVzHm_S0-A
When REM released "Shiney happy people" everybody declared them sell outs, the song with the upbeat hook and dancing in the video was too much. But look closer and you'll find that "Shiney happy people" is anything BUT a happy song, let alone it being about Happy people. It's actually about the Chinese riots at the Tiananmen Square. http://www.youtube.com/watch?v=iCQ0vDAbF7s
Prince's "Let's go crazy" and more obviously "1999" are about mass extinction, due to a global catastrophe. But the driving beat and irresistible groove sure don't give the impression of that. http://www.youtube.com/watch?v=6yB5Dh4F7Es