  We show that a large class of bosonic spin-singlet Fractional Quantum Hall
model wave-functions and their quasi-hole excitations can be written in terms
of Jack polynomials with a prescribed symmetry. Our approach describes new
spin-singlet quantum Hall states at filling fraction nu = 2k/(2r-1) and
generalizes the (k,r) spin-polarized Jack polynomial states. The NASS and
Halperin spin singlet states emerge as specific cases of our construction. The
polynomials express many-body states which contain configurations obtained from
a root partition through a generalized squeezing procedure involving spin and
orbital degrees of freedom. The corresponding generalized Pauli principle for
root partitions is obtained, allowing for counting of the quasihole states. We
also extract the central charge and quasihole scaling dimension, and propose a
conjecture for the underlying CFT of the (k, r) spin-singlet Jack states.
