Letra de Smells like nirvana

What is this song all about?
Can´t figure any lyrics out
How do the words to it go?
I wish you´d tell me, I don´t know
Don´t know, don´t know, don´t know, oh no!
Don´t know, don´t know, don´t know...

Now I´m mumblin´ and I´m screamin´
And I don´t know what I´m singin´
Crank the volume, ears are bleedin´
I still don´t know what I´m singin´
We´re so loud and incoherent
Boy, this oughta bug your parents
Yeah!

*belch*

poing!

It´s unintelligible
I just can´t get it through my skull
It´s hard to bargle nawdle zouss
with all these marbles in my mouth
Don´t know, don´t know, don´t know, oh no!
Don´t know, don´t know, don´t know...

Well, we don´t sound like Madonna
Here we are now, we´re Nirvana
Sing distinctly? We don´t wanna
Buy our album, we´re Nirvana
A garage band from Seattle
Well it sure beats raisin´ cattle
Yeah!

moo..

baa...

And I forgot the next verse
Oh well, I guess it pays to rehearse
The lyric sheet´s so hard to find
What are the words, oh nevermind
Don´t know, don´t know, don´t know, oh no!
Don´t know, don´t know, don´t know...

Well, I´m yellin´ and we´re playin´
But I don´t know what I´m sayin´
What´s the message I´m conveyin´?
Can you tell me what I´m sayin´?
So have you got some idea?
Didn´t think so
Well, I´ll see ya
Sayonara, sayonawa
Ayonawa, hodinawa
Odinaya, yodinaya
Yaddayadda, yaaahyaaah
Ayiyaaaaaah!