Asphodel-ass

bland and uninteresting; middle-of-the-road with no distinguishing features. Sometimes implies it is likely to be forgotten.

Etymology: A reference to the Fields of Asphodel from Greek Mythology. It is the afterlife where normal people go, as opposed with absolutely terrible people who go to tartarus, and good people who go to elysium. In some works, those in asphodel are the only ones to lose their memories, as any asphodel-ass song is easily forgotten.