Onto the song. It's the theme from M*A*S*H, both the movie and the tv show. In the movie, it's used with lyrics; for the tv show, of course, they only used the melancholy music. The title's a little play on words, because while the lyrics work on their own, they're also applicable to the scene in the movie in which the song is featured -- the dentist, whose nickname is "Painless," decides he's going to commit suicide, and his colleagues "help him out."
It's also one of the saddest, most haunting songs I've ever liked. (I generally avoid both slow songs and sad songs.) These lines especially always get me:
The game of life is hard to play
I'm going to lose it anyway
The losing card I'll someday lay
So this is all I have to say.
Damn, that's bleak.
For the record, I think M*A*S*H is a rare instance of a TV show rising above its source material. The movie's okay -- it's certainly acclaimed -- but there's a lot about it that works my nerves. The tv show had more heart and the time to be able to properly explore whatever themes they felt like exploring. As far as the actors, I like Donald Sutherland, but Alan Alda made Hawkeye a world-class smartass and a joy to pay attention to. And Sally Kellerman is a more annoying Hot Lips than Loretta Swit.
You can buy the song here.