  New high-cadence observations with BRITE covering many months confirm that
coupled pairs of nonradial pulsation modes are widespread among early-type Be
stars. With the difference frequency between the parental variations they may
form a roughly sinusoidal variability or the amplitude may cyclicly vary. A
first - amplified - beat pattern is also found. In all three cases the
amplitudes of difference frequencies can exceed the amplitude sum of the base
frequencies, and modulations of the star-to-circumstellar-disk mass-transfer
rate may be associated with these slow variations. This suggests more strongly
than any earlier observations that significant dissipation of pulsational
energy in the atmosphere may be a cause of mass ejections from Be stars. A
unifying interpretative concept is presented.
