We address optical/UV and X-ray variability attributable to orbital signatures from an emitting blob on the accretion disk or in the relativistic jet. Disk based signatures include the quasi-periodic oscillations (QPOs) and its quality factor, and a break frequency in the power spectral density (PSD) shape of the light curve which are used to constrain black hole mass, spin and the emission region size. A general
relativistic (GR) model of jet variability due to an orbiting blob in helical motion along a funnel (or cone) shaped magnetic surface anchored to the accretion disk is then presented. Simulated light curves include
Doppler and gravitational shifts, aberration, light bending and time delay. We find an increased amplitude (~ 12 %); beaming and a systematic phase shift in the light curve compared to that from an earlier special
relativistic model. These results strongly justify the use of a realistic magnetic surface geometry and a fully relativistic calculation. These models are applicable to the study of disk and jet variability in radio, optical and X-ray emission from sources including AGN, X-ray binaries, accreting neutron stars and supermassive binary black holes.