  The Hamiltonian of the $N$-particle Calogero model can be expressed in terms
of generators of a Lie algebra for a definite class of representations.
Maintaining this Lie algebra, its representations, and the flatness of the
Riemannian metric belonging to the second order differential operator, the set
of all possible quadratic Lie algebra forms is investigated. For N=3 and N=4
such forms are constructed explicitly and shown to correspond to exactly
solvable Sutherland models. The results can be carried over easily to all $N$.
