Tablature

Bass Line

E-----------------------------------------------
B-----------------------------------------------
G------------------------6-8--------------------
D----------6-8----------------------------------
A----------------3-4-5-6------------------------
E--3-4-5-6--------------------------------------


the Chords are:

Bb Minor 7 [6-8-6-6-9-6]
Eb Minor 7 [11-13-11-11-14-11]

If you want to improvise the key is Bb Blues