  The Racah algebra encodes the bispectrality of the eponym polynomials. It is
known to be the symmetry algebra of the generic superintegrable model on the
$2$-sphere. It is further identified as the commutant of the $\mathfrak{o}(2)
\oplus \mathfrak{o}(2) \oplus \mathfrak{o}(2)$ subalgebra of $\mathfrak{o}(6)$
in oscillator representations of the universal algebra of the latter. How this
observation relates to the $\mathfrak{su}(1,1)$ Racah problem and the
superintegrable model on the $2$-sphere is discussed on the basis of the Howe
duality associated to the pair $\big(\mathfrak{o}(6)$,
$\mathfrak{su}(1,1)\big)$.
