  This note consists of two parts. Part I is an exposition of (a part of) the
V.Drinfeld's letter, [D].
  The sheaf of algebras of polyvector fields on a Calabi-Yau manifold, equipped
with the Schouten bracket, admits a structure of a Batalin-Vilkovisky algebra.
This fact was probably first noticed by Z.Ran, [R]. Part II is devoted to some
generalizations of this remark.
