In this paper we use results on reducibility, localization and duality for
the Almost Mathieu operator, \[ (H_{b,\phi} x)_n= x_{n+1} +x_{n-1} + b \cos(2
\pi n \omega + \phi)x_n \] on $l^2(\mathbb{Z})$ and its associated eigenvalue
equation to deduce that for $b \ne 0,\pm 2$ and $\omega$ Diophantine the
spectrum of the operator is a Cantor subset of the real line. This solves the
so-called ``Ten Martini Problem'' for these values of $b$ and $\omega$.
Moreover, we prove that for $|b|\ne 0$ small enough or large enough all
spectral gaps predicted by the Gap Labelling theorem are open.