In 1857 Sylvester established an elegant theory that certain counting functions, which he termed denumerants, are quasipolynomials by decomposing them into a polynomial part and a finite set of periodic parts. Each component of the decomposition, called a Sylvester wave, corresponds to a root of unity (the polynomial part corresponding to 1). Recently several researchers, using either combinatorial or complex analytic techniques, obtained explicit formulas for the waves. In this work, we develop an algebraic approach to the Sylvester's theory. Our methodology essentially relies on deriving q-partial fractions of the generating functions of the denumerants, and thereby obtain new and explicit formulas for the waves. The formulas we obtain are expressed in terms of reciprocal polynomial of the degenerate Bernoulli numbers and inverse DFT of a generalized Fourier-Dedekind sum. Further, we also prove certain reciprocity theorems of the generalized Fourier-Dedekind sums and a structure result on the top-order terms of the waves. The proofs rely on our symbolic evaluation operator and our far reaching generalization of the Heaviside's cover-up method for partial fractions.