I'm an amateur guitar player and this song uses chords that I am unfamiliar with. 
I could be completely wrong about these chords, but this is what I hear when I 
listen to it and I can sing the melody over these chords and it blends beautifully.

The chords in this song are strummed using only E, A, and D strings while keeping 
the three higher strings G, B, and e muted.

chords used:

    E A D G B e
G:  3-2-0-x-x-x
A:  5-4-2-x-x-x
D:  5-5-4-x-x-x


Black Mermaid by Esthero

                G    A    D
i?m a black mermaid
                       G    A    D
from the bottom of the sea
                            G    A    D
i will teach you how to love me
                            G    A    D
into greatness i will lead you
                       G    A    D
?cause i?m a black mermaid
                       G    A    D
nothing rarer you will find
                         G    A    D
i am here for you to love me
                          G    A    D
i?ve been here for all o? time
            G               A                 D
and i will wait for you to see me and to understand
        G              A                 D
that a woman can restore the soul of any broken man
           G                  A                D
if you can look beyond the waves and just believe in me?
           G                 A                     D
i am the lighthouse standing strong atop the rocks and sand
                      G    A    D
?cause i?m a black mermaid
                       G    A    D
from the bottom of the sea
                          G    A    D
i will teach you how to love me
                        G    A    D
into greatness i will lead you
              G                A                D
and i?ve spent most of my life deep down inside myself
            G                  A             D
i?ve dreamt about the possibility of someone else
           G                  A                  D
who could see the things i?ve seen and steal away with me
          G                  A                  D
into the darkness we could fade because we know ourselves
                      G    A    D
and i?m his black mermaid
                       G    A    D
from the bottom of the sea
                          G    A    D
i will teach you how to love me
                           G    A    D
into greatness i will lead you
                    G    A    D
yeah i?m a black mermaid 
                       G    A    D
from the bottom of the sea
                         G    A    D
i will teach you how to love me
                         G    A    D
into greatness i will lead you
          G                 A              D
and i?ve spent most of my life deep down inside myself
          G                  A             D
i?ve dreamt about the possibility of someone else
           G                 A              D
who could see the things i?ve seen and steal away with me
           G                 A              D
into the darkness we could fade because we LOVE ourselves
                     G    A    D         
and i?m his black mermaid
                    G    A    D
he thinks i?m beautiful
                      G    A    D
yeah i?m his black mermaid
                     G    A    D
he thinks i?m beautiful
            G    A    D
i am beautiful
G                         A
(All the dark horses and all the good men,
D
won?t you come put me back together again?)   repeatx4
            G    A    D
i am beautiful.


Contact me with questions, comments or corrections, please. Thanks! Hope this is good :D
~Kate