  Within the context of top-down holography, we study a one-parameter family of
regular background solutions of maximal gauged supergravity in seven
dimensions, dimensionally reduced on a 2-torus. The dual, four-dimensional
confining field theory realises the global (spontaneous as well as explicit)
symmetry breaking pattern SO(5)->SO(4). We compute the complete mass spectrum
for the fluctuations of the 128 bosonic degrees of freedom of the
five-dimensional gravity theory, which correspond to scalar, pseudoscalar,
vector, axial-vector, and tensor bound states of the dual field theory, and
includes particles with exotic SO(4) quantum numbers. We confirm the existence
of tachyonic instabilities near the boundaries of the parameter space.
  We discuss the interplay between explicit and spontaneous symmetry breaking.
The SO(5)/SO(4) coset might provide a first step towards the realisation of a
calculable framework and ultraviolet completion of minimal composite Higgs
models, if the four pseudo-Nambu-Goldstone bosons are identified with the real
components of the Higgs doublet in the standard model (SM), and a subgroup of
SO(4) with the SU(2)xU(1) SM gauge group. We exhibit an example with an
additional localised boundary term that mimics the effect of a weakly-coupled
external sector.
