I tried to find the answer to the question asked in the song title using quotes from famous rock hits and 2 /only two/ guitar chords
Let me know if u like it

Well it all started round 1956
A mix of blues n jazz n country sticks
Wild black rhythm and a Gospel choir
but Jimmy`s guitar got it a wild desire

Well it`s one for the money and two for the show
Good Golly Miss Molly sure likes to ball
You never do nothing to save your soul
I said shake rattle and roll but

What the fuck is rock n roll
What the fuck is rock n roll
What the fuck is rock n roll
It's all I need to go
go go go aha
All I need to go , baby Oh yeah

Well, me & my bro we had a rock n roll band
singing in the streets all night
Then came a few really good friends n
helped us to survive

Well it`s one for the money and two for the show
Good Golly Miss Molly sure likes to ball
You never do nothing to save your soul
I said shake rattle and roll but

What the fuck is rock n roll
What the fuck is rock n roll
What the fuck is rock n roll
It's all I need to go
go go go aha
All I need to go , baby Oh yeah

https://shemzee.bandcamp.com/track/what-is-rnr