The phenomenon of melodic interval is described, is distinguished from pitch, and is associated with its physical correlate log frequency ratio. Techniques for measuring performance in tasks of perception of intervals and scales are examined, and a calibrated musical instrument, amelometer, is described. Methods of computation for the results of psychophysical experiments are provided. After a comparison of speech perception and melody perception, bringing out suggestive analogies, some problems for research are outlined. These include the degree and incidence of melody deafness (colloquially tone deafness), the development of melody perception in children and musicians, and inter‐cultural comparisons of perceptual ability for interval