The song lyrics describe Phineas and Ferb's plans to have fun and push boundaries over the summer by "kicking it up a notch." They acknowledge that some may think they have already gone as far as possible, but they insist on going even further. The chorus repeats their determination to kick it up a notch and push through barriers because summer is meant for fun and adventure.

1. KICK IT UP A NOTCH
Phineas & Ferb (feat Slash)
Phineas and Ferb Across the 2nd Dimension Soundtrack
I
(Phineas)
Oh yeah!
If _________ lookin' for fun, baby, _________ a shoo-in
But _________ a little young to be doin' what _________ doin', yeah
We got heads full of dreams and sneakers full of feet
Write the right pronoun + to be (i.e. I’m) structure in the blank spaces
The world is our oyster and life is tastin' sweet
_________ takin' off like __________ in a supersonic jet
But if you think we've gone about as high as we can get, just watch
__________ gonna kick it up a notch
Chorus
Kick it up a notch
Oh, man, you know _________ true
Kick it up a notch
_________ gonna push on through
Kick it up a notch
__________ not content to go with the flow
'Cause everybody knows summer rocks
But now _________ ready to roll [All right Slash let’s roll]
Guitar solo (Slash)
Chorus
(Dr. Doofenshmirtz)
Kick it up a notch
Yeah, crankin' up the evil
Kick it up a notch
I'll cause political upheaval
Kick it up a notch
Yeah, _________ gonna get medieval on you
(Phineas)
Kick it up a notch
Oh, man, you know that's true
Kick it up a notch
__________ gonna push on through
Kick it up a notch
Not gonna go with the flow
'Cause everybody knows summer rocks
But now __________ ready to roll!