  A connection between representation of compact groups and some invariant
ensembles of Hermitian matrices is described. We focus on two types of
invariant ensembles which extend the Gaussian and the Laguerre Unitary
ensembles. We study them using projections and convolutions of invariant
probability measures on adjoint orbits of a compact Lie group. These measures
are described by semiclassical approximation involving tensor and restriction
mulltiplicities. We show that a large class of them are determinantal.
