  Halpern and Yamron have given a Lorentz, conformal, and Diff S$_2$-invariant
world-sheet action for the generic irrational conformal field theory, but the
action is highly non-linear. In this paper, we introduce auxiliary fields to
find an equivalent linearized form of the action, which shows in a very clear
way that the generic affine-Virasoro action is a Diff S$_2$-gauged WZW model.
In particular, the auxiliary fields transform under Diff S$_2$ as local Lie $g$
$\times$ Lie $g$ connections, so that the linearized affine-Virasoro action
bears an intriguing resemblance to the usual (Lie algebra) gauged WZW model.
