Apart from the singing this song would have to be one of Nirvana's best.
This tab took me hours i nearly lost my mind... ah well. 
Tabbed by Cal B. (Mail me at Cal_C1@hotmail.com) 

DROP D TUNING (standard tuning 1/2 step down)

INTRO
--5-X-5-X-5-X--5--I
--5-X-5-X-5-X--5--I
--3-X-3-X-3-X--3--I
4-----------------I
------------------I
------------------I


Intro Riff 2
---------------I------------------------I------------I----------------------I
10--11---12----I-13-------------14-14/--I-13---------I-13\12-12\10-10/12-12-I
--8----9----10-I----11-11-12-12---------I-12---------I-12\11-11\9--9-/11-11-I
---------------I------------------------I------------I----------------------I
---------------I------------------------I------------I----------------------I
---------------I------------------------I------------I----------------------I


---------------I------------------------I------------I----------------------I
9---10---11----I-12-------------13-13/--I-13---------I-13\12-12\10-10/12-12-I
--7----8----9--I----10-10-11-11---------I-12---------I-12\11-11\9--9-/11-11-I
---------------I------------------------I------------I----------------------I
---------------I------------------------I------------I----------------------I
---------------I------------------------I------------I----------------------I


Intro After "You Rang"

---------------I------------------------I------------I----------------------
10--11---12----I-13-------------14-14/--I-13---------I-13\12-12\10-10/12-12-
--8----9----10-I----11-11-12-12---------I-12---------I-12\11-11\9--9-/11-11-
---------------I------------------------I------------I---------------------twice
---------------I------------------------I------------I----------------------
---------------I------------------------I------------I----------------------

----------I----------------I
----------I----------------I
----------I----------------I
----------I----------------I 4 times
9/10------I10\9-9\7-7/9-9--I
7/8-------I8-\7-7\5-5/7-7--I


CHORUS

F5
-----I-----I
-----I-----I
-----I-----I
3----I-----I 4 times
3----I-----I
1----I-----I


OUTRO 
----------------I----------------I
----------------I----------------I
----------------I----------------I 4 TIMES
----------------I----------------I
9-8---8-7---7-6-I---6-5---5-4-3--I
7-6-0-6-5-0-5-4-I-0-4-3-0-3-2-1--I
    PM    PM     PM    PM 


Bit of a crazy song but i like it. (Imagine how high or stoned or manicly
depressed to sing like that and not notice anything weird about it...
especially during the outro)... ah well who cares!!!