Interstellar Overdrive by Pink Floyd
Music by Syd Barrett

This is the main guitar riff which appears as
the intro and in various places thoughout
the song.

E5 (heavily palm muted) repeated using downstrokes
then

A A Ab A Ab  
G G Gb G Gb   
FFFFFFF GG E5

B B Bb B Bb  
A A Ab A Ab   
GGGGGGG AA E5

use barre chords.

then everything goes a bit mad!!!

if you can't get the rhythm correct try thinking
of the theme tune to "Steptoe and son" because
it's almost the same..

steve