The application to organ tones or other sustained musical sounds of the Stevens and the Zwicker methods for loudness‐level calculation from observed sound spectra is examined. It is found that both methods, although developed for dealing with noise of the continuous spectrum type, are applicable to organ tones, a particular class of discrete component sound, subject to the use in both methods of accepted equal‐loudness contours. Examples of the loudness levels of some typical organ tones are given. Questions needing further investigation are noted.