Sorrow Singer was a Sphinxian treecat and a memory singer of the Black Rock Clan. She was slender, and had white and brown fur. She was the only known survivor of the clan, because she was visiting her brother who had bonded into Moonlight Dancing Clan when the Black Rock home range was destroyed by the Mesan Operation Oyster Bay. (HH13) In June 1922 PD she proposed to Dances on Clouds to have treecats become bodyguards to humans to defend against the Mesan Alignment's nano-tech assassination methods.