Here is the chords to Sing It by Rebecca Black. Its really easy and simple

Capo 1st Fret
 
Chords used throughout song: D A Bm G

  [Intro]

Woah-oh Woah-oh-oh-oh
Woah-oh Woah-oh-oh-oh
Woah-oh Woah-oh-oh-oh
Woah-oh Woah-oh

[Verse 1]
That familiar voice
It speaks to me
Tells me everything is gonna be ok
It's meant to, meant to be

Sun is out
And the darkness fades
Got my headphones on and I'm under
In a dream but I'm wide awake

Woah-oh Woah-oh-oh-oh

[Chorus]
Turn it up, turn it up
Play it aloud
Sing it from my heart
Sing it from my heart, yeah, yeah, yeah, yeah
It's alright, it's alright
Alri-i-i-ight

Turn it up, turn it up
I feel ya now
Sing it from the heart
Sing it from the heart, yeah, yeah, yeah, yeah
It's alright, it's alright
Be alright

[Verse 2]
On brighter days
You make me smile
When I've got you here with me
I could walk a million, billion miles

I'm dreaming again
So get outta my way
Life goes fast, so you gotta make it last
No matter what they say

Woah-oh Woah-oh-oh-oh

[Chorus]
Turn it up, turn it up
Play it aloud
Sing it from my heart
Sing it from my heart, yeah, yeah, yeah, yeah
It's alright, it's alright
Alri-i-i-ight

Turn it up, turn it up
I feel you now
Sing it from my heart
Sing it from my heart, yeah, yeah, yeah, yeah
It's alright, it's alright
Be alright

[Ending]
Live it up, live it up, live it up, yeah!
Live it up, live it up, live it up, yeah!
Live it up, live it up, live it up, yeah!