  We perform Raman scattering experiments on natural graphite in magnetic
fields up to 45 T, observing a series of peaks due to interband electronic
excitations over a much broader magnetic field range than previously reported.
We also explore electron-phonon coupling in graphite via magnetophonon
resonances. The Raman G peak shifts and splits as a function of magnetic field,
due to the magnetically tuned coupling of the E2g optical phonons with the K-
and H-point inter-Landau-level excitations. The analysis of the observed
anticrossing behavior allows us to determine the electron-phonon coupling for
both K- and H-point carriers. In the highest field range (>35 T) the G peak
narrows due to suppression of electron-phonon interaction.
