The initial section of the intro is really quick and is probably an ad-lib from Freddie  
all based around E, E7sus4 and E7 with runs down through the scall with a few trills in it. 
Then the main intro starts, continuing through the song. 
Eb   Bb/D  Cm 
 
Cm 
    Another party's over 
Gm 
    And I'm left cold sober 
  F#?           Fm7          E? 
 My baby left me  for somebody  new 
Fm 
    I don't want to talk about it 
Abm                               Eb/G    F#? 
    Want to forget about it, wanna Be intoxicated with that 
 Fm7     Bb7      
 Special brew  
                Eb       G7 
So come and     get me    Let me 
Ab            Abm 
   get in that sinking feeling 
Eb              F#?          Fm7 
   that says my heart is on an all-time low 
   Bb7              Eb 
   So        don't expect me 
G7 
   To behave perfectly 
Ab               Abm 
   And wear that sunny smile 
Eb/G          F#? 
   My guess is I'm in for a 
   Fm7 
   cloudy and overcast 
F#? 
   Don't try and stop me cos I'm 
   Eb/G            E?           Fm     Fm    Fm7M  Fm7 
   heading for that stormy weather soon  
Ab 
   I'm causing a mild sensation 
Abm 
   With this new occupation 
Eb/G              Cm 
   I'm permenantly glued to 
   Gm                 Cm                   Fm7 
   this extraordinary mood.  So now move o- ver   let me take 
F#? 
over    with my 
Fm7   F#?      Ab7   Bb7    Eb 
      Mel - an - chol - y      Blues 

Solo :  
Eb  Bb/D  Bm/D   Cm7   Ab   Abm   Eb/G   F#?   Fm   F#?   E/G    E?   Fm  Fm^  Fm-7M  Fm7  
 
Ab 
   I'm causing a mild sensation 
Abm 
   With this new occupation 
Eb/G          Cm 
   I'm in the news 
   Gm               Cm              Fm7 
   I'm just getting used to my new exposure 
F#? 
   So come into my enclosure 
 
And meet my 
Fm7  F#?     Ab7   Bb7    Eb 
    Mel - an - chol - y      Blues 
 
Album Ending : Song Fades out using the following Chords to the same style / melody of the piece. 
E   B/D   Bm/D   Cm7   A   Am   E/G   F#?   Fm   F#?   Fm7   F#?   A7   B7   E 
Concert Ending : Song uses the Album Ending chords and resolves on E - obviously with no fade. 
  
Performance Notes :  

^ means the chord is played on 1 octave higher on the register. 

Ad-Libbing on the song can be achieved by trilling on neighboring notes on the scale / chord. 

Listening to the Album / Concert version will allow you to place a more-true ad-lib. 

The song also contains many 7th and diminished notes. 

The timing in the song is a little unusual in that its very free and chords are often played  

in advance of the words - best bet is to listen to the piece on the album a few times to get 

the idea.