A method performed by one or more processing devices includes receiving information indicative of an input chord progression, with the input chord progression comprising a plurality of chords; identifying chord changes in the plurality of chords; identifying, based on the chord changes, moving tones in the input chord progression; selecting, from the moving tones, guide tones that provide an outline of a harmony to be used in generating a synthesized melody; generating, based on the selected guide tones and one or more interpolation operations, interpolation tones for interpolation among the guide tones; and generating, based on interpolation of the interpolation tones with the guide tones, the synthesized melody.