OncomingStorm12th proposes a new name "Nocturne (The Singer Not the Song)"; Amorkuz proposes a new name "King Nocturne"
Talk about it here.
The Nocturne was a conceptual being imprisonned inside another universe along with Sutehk and a number of other godlike beings who were a threat to the Doctor's universe. (COMIC: The jazz monster)
Biology
The Nocturne was a conceptual being made of living sound. Its true form was that of a monstrous worm-like creature which towered over humans. It had multiple legs, eyes and mandibles and its body was a red color with a pale outline. (COMIC: The jazz monster)
Powers and abilities
The Nocturne, like any conceptual being, was according to the Tenth Doctor, " very versatile". It could manipulate sound for various and creative purposes.
On Wupatki, the Nocturne hid itself as a virus inside songs broadcast from a radio station. The virus could infect the Shan'tee, another race of conceptual beings made of living sound.