  We extend the axiomatization for detecting and quantifying sign changes of
Meher and Murty to sequences of complex numbers. We further generalize this
result when the sequence is comprised of the coefficients of an $L$-function.
As immediate applications, we prove that there are sign changes in intervals
within sequences of coefficients of GL(2) holomorphic cusp forms, GL(2) Maass
forms, and GL(3) Maass forms. Building on previous works by the authors, we
prove that there are sign changes in intervals within sequences of partial sums
of coefficients of GL(2) holomorphic cusp forms and Maass forms.
