Waves at all scales, ranging in wavelength from the size of a loop (fraction of a solar radius) down to the gyroradii of coronal ions (about hundred meters), are believed to play a key role in the transport of mechanical energy from the chromosphere to the Sun's corona and wind, and through the dissipation of wave energy in the heating and sustaining of the solar corona. A concise review of new observations and theories of waves in the magnetically confined (loops) as well as open (holes) corona is given. Evidence obtained from spectroscopy of lines emitted by coronal ions points to cyclotron resonance absorption as a possible cause of the observed emission-line broadenings. Novel remote-sensing solar observations reveal low-frequency loop oscillations as expected from MHD theory, which appear to be excited by magnetic activity in connection with flares and to be strongly damped. Kinetic models of the corona indicate the importance of wave-particle interactions that hold the key to understand ion acceleration and heating by high-frequency waves.