Sleepwalk by Santo and Johnny. It’s in every film set in the '50s or '60s and has its own website but hardly anyone can name it.
Tygr, Powerhouse has a couple of distinct movements; one of them is used for factory scenes, which is what the piece was meant to evoke, and another is used when someone is sneaking up on someone else. You can hear clips from this piece and others at the official website, here. Each of the pieces available for listening to have been used in Warner Brothers cartoons - there’s a page on that site that lists all of 'em, too. I love Raymond Scott, and force his instrumentals into the ears of anyone who rides in my car. 
Suzanne Vega’s song “Tom’s Diner,” usually known as “that song that goes doo-doo-doo-doo, doo-doo-doo-doo, doo-doo-doo-doo-doo-doo-doo-doo.”
Ah, but what’s the opening theme music to a Bugs Bunny cartoon called?
You know, the one that starts with some weird glissando, then immediately launches into trumpets going “DAH, da da da DA DA DA da da da da da, DAH, da da da DA DA DA da da da da da,” then has the cello section play a counter melody, then has a REAL quick descending scale on a piano, then has a xylophone play the first half of the opening trumpet theme again, then closes with trumpets going, “Da da da dah, dah DAAAAAAA!”
The Merrie Melodies theme from 1936 onward was “Merrily We Roll Along” by Charles Tobias, Murray Mencher, and Eddie Cantor.
That was the Four Tops.
“Be Thankful for What You’ve Got” - William DeVaughn
The only line I can recall:
“Diamond in the back, sunroof top
Makin’ the scene with a gangster lean…”
Several pieces by Leroy Anderson were used in many different cartoons: The Typewriter Song, The Syncopated Clock, Sandpaper Ballet. Also, The Rakes of Mallow (and the similar The Irish Washerwoman) is familiar to anyone that saw The Quiet Man.
How 'bout that sailor-ish tune they often play on a xylophone in Popeye, when he’s not eating his spinach?
Thought of another one that stumped me for a good while.
“Please Tell Me Who I Am” by Supertramp …
is actually titled “The Logical Song”.
…
How about also “Fanfare for the Common Man” by Emerson, Lake and Palmer? That’s an instrumental frequently heard on classic-rock stations that give play to '70s art rock.
…
Here’s a personal stumper – what’s that “Ey! Oh! Let’s Go!” song? It’s kind of punk-sounding, and is used a lot in commercials (including a current one I can’t remember very well … just saw it today):
*Ey! Oh! Let’s Go!
Ey! Oh! Let’s Go!" *
???
“Sailor’s Hornpipe”, and here’s a charming MIDI file of it.
What’s the name of that Jimmy Buffet song?
You know…“Wasted away again in Margaritaville…searchin for my lost shaker of salt…some people claim that there’s a woman to blame…”
Everyone can sing it (well for the most part anyway, I never met a drunk that wouldn’t try )
But, few know the title.
There is a nice MIDI rendition of the Powerhouse B theme on this page; it’s titled machine.mid.
Okay, I’ll bite…I’ve always heard it called Margaritaville. It seems that Jimmy Buffett would agree. Am I being whooshed? 
Fear Itself - but the second Powerhouse MIDI on that page (RUNNER) doesn’t have percussion! When you take the drums out of Powerhouse you’re screwing with Raymond Scott’s holy artistic genius vision and ::head explodes::
Sorry, I get annoying with my Powerhouse.
Lily please excuse me, I have my songs mixed up. I was thinking about the Pina Colada song NOT Margaritaville…sorry, I am drinking a Margarita, maybe that’s what threw me.
You know…"if you like pina coladas…gettin caught in the rain…etc. :smack:
Blitzkreig Bop, by the Ramones.
Well then, keep your drinks straight! 
It seems to be Escape (The Pina Colada Song), by Rupert Holmes.
Damn, Wumpus beat me to the Grieg reference, but most of that work (Suite No.1, Op.46) is recognisable once you hear it (not just the “Dawn” portion, but “The Death of Ase” and “In the Hall of the Mountain King” as well).
The theme song from the “King of the Hill” TV program is called “Yahoos and Triangles”, and most have probably heard that.
What about those 1, 2, or maybe 3 ominous-sounding instrumentals that movie studios have been using in almost all 30 second action/horror/sci-fi movie trailers in recent years? I just saw a new one today, and I swore it was different, that it was a piece from the Lord of the Rings saga, but I could be wrong. Anyone?
“Dial a Line” by Simon & Garfunkel is actually titled “The Boxer”.
[sub](Baby-boomer S&G fans gasp at the blasphemous lack of fundamental musical knowledge)[/sub]