  We use data from the Rossi X-ray Timing Explorer to search for harmonics and
sidebands of the two simultaneous kilohertz quasi-periodic oscillations (kHz
QPOs) in Sco X-1. We do not detect any of these harmonics or sidebands, with
95% confidence upper limits to their power between ~ 1% and ~ 10% of the power
of the upper kHz QPO. The oscillations produced at these frequencies may be
attenuated in a scattering corona around the neutron star. We find that upper
limits to the unattenuated power of some of the strongest theoretically
predicted harmonics and sidebands are as low as ~ 2% of the unattenuated power
of the high-frequency QPO in Sco X-1.
