  We study the quasi-normal modes of asymptotically anti-de Sitter black holes
in a class of shift-symmetric Horndeski theories where a gravitational scalar
is derivatively coupled to the Einstein tensor. The space-time differs from
exact Schwarzschild-anti-de Sitter, resulting in a different effective
potential for the quasi-normal modes and a different spectrum. We numerically
compute this spectrum for a massless test scalar coupled both minimally to the
metric, and non-minimally to the gravitational scalar. We find interesting
differences from the Schwarzschild-anti-de Sitter black hole found in general
relativity.
