  First we reprove, using representation theory and the relative trace formula
of Jacquet, an average value result of Duke for modular L-series at the
critical center. We also establish a refinement. To be precise, the L-value
which appears is L(1/2, f)L(1/2,f,\chi) (divided by the Petersson norm of f),
and the average is over newforms f of prime level N and coefficients a_p(f),
with \chi being an odd quadratic Dirichlet character of conductor -D and
associated quadratic field K. For any prime p not dividing ND, the asymptotic
as N goes to infinity is governed by a measure \mu_p, which is the Plancherel
measure at p when \chi(p)=-1, but is new if \chi(p)=1; as p goes to infinity
both measures approach the Sato-Tate measure. A particular consequence of our
refinement is that for any non-empty interval J in [-2,2], there are infinitely
many primes N, which are inert in K, such that for some f of level N, a_p(f) is
in J and L(1/2, f)L(1/2,f,\chi) is non-zero.
