  It is proved that whenever a zero entropy dynamical system $(X,T)$ has only
countably many ergodic measures and $\mu$ stands for the arithmetic M{\"o}bius
function, then there exists a subset $A$ of integers depending only on the
system, of logarithmic density one, such that for each $f$ continuous on $X$,
$\frac1N \sum_{n\leq N} f(T^nx)\mu(n) \to 0$ as $N\to\infty$, $N\in A$,
uniformly in $x\in X$. In particular, the density version of M{\"o}bius
orthogonality holds.
