"Black & Bleach", recorded by Further Down, is a song featured in the Person of Interest episode “Identity Crisis”. It is played in the bar where Reese and Fusco meet to discuss a possible suspect in an identity theft case, who happens to work in that bar.
Black & Bleach is one of the few songs that is source music (sometimes called diegetic music). Unlike the episode's score, source music is heard by the characters in an episode and originates within the story itself.
The song's lyrics can be found here.