  We start with a (q,t)-generalization of a binomial coefficient. It can be
viewed as a polynomial in t that depends upon an integer q, with combinatorial
interpretations when q is a positive integer, and algebraic interpretations
when q is the order of a finite field. These (q,t)-binomial coefficients and
their interpretations generalize further in two directions, one relating to
column-strict tableaux and Macdonald's ``seventh variation'' of Schur
functions, the other relating to permutation statistics and Hilbert series from
the invariant theory of GL_n(F_q).
