  With the aim to study six-dimensional (2,0) superconformal theories with
non-Abelian tensor multiplets we propose a five-dimensional superconformal
action with eight supersymmetries for an infinite tower of non-Abelian vector,
tensor and hypermultiplets. It describes the dynamics of the complete spectrum
of the (2,0) theories compactified on a circle coupled to an additional vector
multiplet containing the circle radius and the Kaluza-Klein vector arising from
the six-dimensional metric. All couplings are only given in terms of group
theoretical constants and the Kaluza-Klein levels. After superconformal
symmetry is reduced to Poincare supersymmetry we find a Kaluza-Klein inspired
action coupling super-Yang-Mills theory to an infinite tower of massive
non-Abelian tensors. We explore the possibility to restore sixteen
supersymmetries by using techniques known from harmonic superspace. Namely,
additional bosonic coordinates on a four-sphere are introduced to enhance the
R-symmetry group. Maximally supersymmetric Yang-Mills theories and the Abelian
(2,0) tensor theories are recovered as special cases of our construction.
Finally, we comment on the generation of an anomaly balancing Wess-Zumino term
for the R-symmetry vector at one loop.
