  We introduce a novel test of General Relativity in the strong-field regime of
a binary black hole coalescence. Combining information coming from Numerical
Relativity simulations of coalescing black hole binaries with a Bayesian
reconstruction of the gravitational wave signal detected in LIGO-Virgo
interferometric data, allows one to test theoretical predictions for the
instantaneous gravitational wave frequency measured at the peak of the
gravitational wave signal amplitude. We present the construction of such a test
and apply it on the first gravitational wave event detected by the LIGO and
Virgo Collaborations, GW150914. The $p$-value obtained is $p=0.48$, to be
contrasted with an expected value of $p=0.5$, so that no signs of violations
from General Relativity were detected.
