  I consider a simple model of a three-band superconductor with repulsive
interband interactions. The frustration, associated with the odd number of
bands, leads to the possible existence of an intrinsically complex
time-reversal symmetry breaking (TRSB) order parameter. In such state the
fluctuations of the different gaps are strongly coupled, and this leads to the
development of novel collective modes, which mix phase and amplitude
oscillations. I study these fluctuations using a simple microscopic model and
derive the dispersion for two physically distinct modes, which are gapped by
energy less than twice the gap, and apparently present for all values of
interband couplings.
