A simple description of the KP hierarchy and its multi-hamiltonian str
ucture is given in terms of two Bose currents. A deformation scheme co
nnecting various W-infinity algebras and the relation between two fund
amental nonlinear structures are discussed. Properties of Faa di Bruno
polynomials are extensively explored in this construction. Applicatio
ns of our method are given for the Conformal Affine Toda model, WZNW m
odels and discrete KP approach to Toda lattice chain.