E.T. is a dark pop song that talks about extraterrestrial romance (or sex), while Hummingbird Heartbeat is a fun song that talks about birds and bees (making love)
Beyoncé On Top - Beyoncé
I Am... Sasha Fierce
If I Were a Boy
Single Ladies (Put a Ring on It)
Mitchie - Christina Aguilera
The Masquerade
Welcome
Birds of Prey
vatsal - Taylor Swift
You're The Best Thing Thats Ever Been Mine....Or Maybe Just Another Picture To Burn
Mine
Picture To Burn
Strangergab - Hilary Duff
Hilary Duff Black and White
Wake Up
Burned
Nait Phoenix - Brandy
Dark Heroine
All in Me
Romeo & Juliet
fiercE - Jason Mraz
Lucky or not so Lucky
A Beautiful Mess
Lucky
Mr. Loco - Maroon 5
Sleep... Wake up!
Wake Up Call
Goodnight Goodnight
It's totally opposite musically, lyrically (in GG, he apologized for "having hurt his little girl", while in the other one he blames her for "catching her in the morning with another one in his bed"). Even the titles are the opposite.
Katie - Britney
It's About Growth
Baby One More Time
Stronger
♥jONE731♥ - Avril Lavigne
D Flipping Lavigne
When you're gone
What the hell
MusicLoverDude - Miley Cyrus
Not a Kid Anymore
The Climb
Permanent December
Owl - Björk
Independence or Unity?
Declare Independence
Cocoon
Not only are they different musically, they're also different lyrically. One of them is about breaking free or declaring independence and the other is about declaring your love for someone;unity.