Friday by Rebacca Black, but then with different text and the Hetalia characters!
Things that are written between ~..~ should not be sung, same with the names of the people who (should) sing it! Have fuuun

-----------------------
~America's house~
America:
Nine a.m., waking up in the morning
Gonna be late, gonna get problems
Gotta get my bro, gotta get Israel

~At the meeting~
England:
Seein' magicalthings,
Germany:
His mind is goin'
China:
Freakin' out because,
Russia:
Everybody is Russian

~Going back to America~
America:
Gotta get down to the meetin'
Gonna crash this car, I see my Allies (Allies)

~WW2~
Allies:
Kickin' ass of Axis
Axis:
Beated up by Allies
Allies:
Gotta end this war now
Axis:
How could we do that?

~Present day~
Lithuania:
It's Poland, Poland
The Netherlands:
Gotta smoke pod with Poland
England:
Everybody is lookin' forward to Olympics, lympics
Lithuania:
Poland, Poland
The Netherlands:
Smokin' pod with Poland
England:
Everybody is lookin' forward to Olympics

Canada:
Canada, Canada
Kumajiro:
Who?
Canada:
Canada, Canada
Kumajiro:
Who?
Romano:
Spain! Spain! Spain! Spain!
England:
Lookin' forward to Olympics

~You will see~
England:
Some time later, we're sailin' at some ocean
America:
Cruisin' so fast, I need to puke
China:
Ew
Russia:
Strand, strand, strand, think we've stranded

~In the SU~
Russia:
You know the Baltics
Latvia:
I Baltic, you Baltic
Russia:
Now start growing

~WW2~
Axis:
Kickin' ass of Allies
Allies:
Beated up by Axis
Axis:
Gotta end this war now
Allies:
How could we do that?

~Present day~
Lithuania:
It's Poland, Poland
The Netherlands:
Gotta smoke pod with Poland
England:
Everybody is lookin' forward to Olympics, lympics
Lithuania:
Poland, Poland
The Netherlands:
Smokin' pod with Poland
England:
Everybody is lookin' forward to Olympics

Canada:
Canada, Canada
Kumajiro:
Who?
Canada:
Canada, Canada
Kumajiro:
Who?
Romano:
Spain! Spain! Spain! Spain!
England:
Lookin' forward to Olympics

America:
Yesterday was meeting, meeting
England:
Get off m-me frog, frog
France:
Le gaspin'
Canada:
He-he-he sits on me
He sits on me
Germany:
We gotta talk about Issues!

France:
Zhis meeting is so uzeless
England:
And nothing gets deci...ded
America:
I so want this meeting to end

America:
U.S., United States

~At the ending of WW2~
Allies:
So we kicked ass of Axis
Now it is finished
Axis:
Now it is finished

~In a pub~
England:
I'm drinkin', cryin'
America:
Fuck no

~We'll all become one with mother Russia~
Russia:
Big land, crushin' lands
Wit' a lead pipe at my side

~Back at the pub~
Kumajiro:
Who?
Canada:
Matthew
America:
Passin' out is
Canada:
Eh?
America:
Arthur in front of me

~Some other time~
Prussia:
Sprechst!
Gilbird:
Py-o, py-o
America:
Want ice cream
Poland:
Like totally
Lithuania:
It's Poland

~Lol wut~
America:
It's England
Romano:
We gotta fin Spain
Moron, moron, y're

Lithuania:
It's Poland, Poland
The Netherlands:
Gotta smoke pod with Poland
England:
Everybody is lookin' forward to Olympics, lympics
Lithuania:
Poland, Poland
The Netherlands:
Smokin' pod with Poland
England:
Everybody is lookin' forward to Olympics

Canada:
Canada, Canada
Kumajiro:
Who?
Canada:
Canada, Canada
Kumajiro:
Who?
Romano:
Spain! Spain! Spain! Spain!
England:
Lookin' forward to Olympics

Lithuania:
It's Poland, Poland
America:
Where the fuck lies Poland?
England:
America, you should buy a ma-ap, ma-ap
America:
Have one, have one
But I can not find it
England:
America, I mean a world map

Romano:
Bastardo! Bastardo!
Italy:
Pasta~
Romano:
Bastardo! Bastardo!
Italy:
Pasta~
Denmark:
Norge, Norge, Norge, Norge
Australia:
Chillin' with a kangaroo