A dark-haired man standing up singing and a man in a brown hat sitting playing guitar .
It is impossible that a blues duo of singer and guitarist is giving a performance at an open mic night .
Chances are about even that a blues duo of singer and guitarist is giving a performance at an open mic night .
It is impossible that a blues duo of singer and guitarist is giving a performance at an open mic night .
A blues duo of singer and guitarist is giving a performance at an open mic night .