  We study properties of compactly supported, 4 parameter \newline $(\rho
_{12},\rho _{23},\rho _{13},q)\in (-1,1)^{\times 4}$ family of continuous type
3 dimensional distributions, that have the property that for $q\rightarrow
1^{-}$ this family tends to some 3 dimensional Normal distribution. For $q=0$
we deal with 3 dimensional generalization of Kesten--McKay distribution. In a
very special case when $\rho _{12}\rho _{13}\rho _{23}=q$ all one dimensional
marginals are identical, semicircle distributions. We find both all marginal as
well as all conditional distributions. Moreover, we find also families of
polynomials that are orthogonalized by these one-dimensional margins and
one-dimensional conditional distributions. Consequently, we find moments of
both conditional and unconditional distributions of dimensions one and two. In
particular, we show that all one-dimensional and two-dimensional conditional
moments of, say, order $n$ and are polynomials of the same order $n$ in the
conditioning random variables. Finding above mentioned orthogonal polynomials
leads us to a probabilistic interpretation of these polynomials. Among them are
the famous Askey-Wilson, Al-Salam--Chihara polynomials considered in the
complex, but conjugate, parameters, as well as q-Hermite and Rogers
polynomials. It seems that this paper is one of the first papers that give a
probabilistic interpretation of Rogers (continuous q-ultraspherical)
polynomials.
