  Far from resonance, the coupling of the G-band phonon to magneto-excitons in
single layer graphene displays kinks and splittings versus filling factor that
are well described by Pauli blocking and unblocking of inter- and intra- Landau
level transitions. We explore the non-resonant electron-phonon coupling by
high-magnetic field Raman scattering while electrostatic tuning of the carrier
density controls the filling factor. We show qualitative and quantitative
agreement between spectra and a linearized model of electron-phonon
interactions in magnetic fields. The splitting is caused by dichroism of left
and right handed circular polarized light due to lifting of the G-band phonon
degeneracy, and the piecewise linear slopes are caused by the linear occupancy
of sequential Landau levels versus $\nu$.
