  We show that for a noetherian algebra $A$ whose bounded dg derived category
is smooth, the singular Hochschild cohomology (=Tate--Hochschild cohomology) is
isomorphic, as a graded algebra, to the Hochschild cohomology of the dg
singularity category of $A$. The existence of such an isomorphism is suggested
by recent work of Zhengfang Wang.
