  The collective mode spectrum of a symmetry-breaking state, such as a
superconductor, provides crucial insight into the nature of the order
parameter. In this context, we present a microscopic weak-coupling theory for
the collective modes of a generic multi-component time-reversal symmetry
breaking superconductor, and show that fluctuations in the relative amplitude
and phase of the two order parameter components are well-defined underdamped
collective modes, even in the presence of nodal quasiparticles. We then
demonstrate that these "generalized clapping modes" can be detected using a
number of experimental techniques including ac electronic compressibility
measurements, electron energy loss spectroscopy, microwave spectroscopy, and
ultrafast THz spectroscopy. Finally, we discuss the implications of our work as
a new form of "collective mode spectroscopy" that drastically expands the
number of experimental probes capable of detecting time-reversal symmetry
breaking in unconventional superconductors such as
Sr$_{\text{2}}$RuO$_{\text{4}}$, UTe$_{\text{2}}$, and moir\'e
heterostructures.
