(They don't necessarily need to have become hits to qualify for this thread.)

Starting with what might the most obvious one, "Overnight Sensation (Hit Record)" by The Raspberries:

Silent Noise - Hit Record

Brook Benton - Hit Record

Heart included the facetiously titled "Hit Single" on their first greatest hits album. Actually a sound collage of studio chatter.

What Kind Of Girl Do You Think We Are? - Frank Zappa
(partial lyrics)

Look What They've Done To My Song Ma - Melanie
Joe's Garage - Frank Zappa

Big In Japan — Shane Nicholson
Top Of The Pops — Smithereens
Hit Single — Joe Jackson

Hit Single #1 - Hot Tuna

(title only)

We Got A Hit - The Who

The Entertainer - Billy Joel

"You've heard my latest record
It's been on the radio
Ah, it took me years to write it
They were the best years of my life
It was a beautiful song
But it ran too long
If you're gonna have a hit
You gotta make it fit
So they cut it down to 3:05"

They Called It Rock--Nick Lowe

They went and cut the record, the record hit the charts
Someone in the newspaper said that it was art
The disco casanova had it heavy on the breath
The local teeny-bopper band was playing it to death

They called it rock

The telephones are ringing, the boys are getting hot
They're jettin' out to Rio and some other sunny spots
Some senorita says the singer sounds terrific
The personal appearances are stopping the traffic

They called it rock

Hey long distance, it's a rock and roll romance
CBS is gonna pay a great big advance
Hey Atlantic, come on take a chance
Arista say they love it but the kids can't dance to it

They cut another record, it never was a hit
Someone in the newspaper said it was shit
The drummer is a bookie, the singer is a whore
The bass player's selling clothes he never would have wore

They called it rock

Hitsville UK--The Clash. (I love this song)

♫ The band went in/and knocked 'em dead/in 2 minutes 59... ♪

I was just thinking last night before I fell asleep about songs about the band itself, or about the singer or songwriter himself, or about how much the music industry sucks.

Songs about a hit single itself:

The Hook - Blues Traveler
Pork & Beans - Weezer (the part about Timbaland)
Back to the Shack - Weezer (the whole first verse)
Sell Out - Squirrel Nut Zippers
Into the Great Wide Open - Tom Petty

Rosalita - Bruce Springsteen

♫ Well, tell him this is his last chance to get his daughter in a fine romance
Because the record company, Rosie, just gave me a big advance ♪

Judy In Disguise (With Glasses) by John Fred and his Playboy Band was a parody about Lucy In The Sky With Diamonds.

Skyhooks - Million Dollar Riff

Top of the Pops - Kinks
Hey Mister That's Me Up On the Jukebox - James Taylor

Paul Davis - "Superstar" is a triple. It mentions 3 songs; "Philadelphia Freedom" by Elton John, "Heart Like A Wheel" by Linda Ronstadt and "Help Me" by Joni Mitchell.

Sequel (Taxi) — Harry Chapin
Let’s Twist Again — Chubby Checker

Tom Petty - Runnin' Down a Dream

It was a beautiful day, the sun beat down
I had the radio on, I was drivin'
Trees flew by, me and Del were singin' little Runaway
I was flyin'

Back up, guys. Sequels is a different topic, as is "songs about other songs". (And they're good topics. Somebody make those threads.)

This thread is supposed to be songs about the concept of a hit record itself.

Unreleased and only played in public once, but:

Beatles Forever - ELO
(Names about 20 Beatles Songs)

And...

Shangri-la - ELO

My Shangri-La has gone away
Faded like the Beatles on 'Hey Jude'
She seemed to drift out on the rain
That came in somewhere softly from the blue