  We derive an explicit sum formula for symmetric Macdonald polynomials. Our
expression contains multiple sums over the symmetric group and uses the action
of Hecke generators on the ring of polynomials. In the special cases $t=1$ and
$q=0$, we recover known expressions for the monomial symmetric and
Hall-Littlewood polynomials, respectively. Other specializations of our formula
give new expressions for the Jack and $q$-Whittaker polynomials.
