To sing or serenade into one's bumhole therefore mimicking the action of singing into a microphone that happens to be brown. Often ex-American/Canadian Idol stars are reduced to using the brown microphone since it is the only audience that is attentive.
Tariq: "Last nightt Clay Aiken sang an incredible melody into m'a brown microphone. It was stuck in m'a head awl day!"
Dwayne: "Damn nigga, that's gross!"