Tonal scale step encoding and the recognition of octave-scrambled melodies

Abstract

Octave-scrambled melodies, having their pitches randomly distributed over several octaves, are difficult to recognize. Such melodies do not preserve pitch-interval patterns of undistorted melodies, but only their sequences of chromas—that quality of pitch shared by tones an octave apart. It was shown previously [W. J. Dowling, J. Acoust. Soc. Am. Suppl. I 64, S146 (1978)] that such melodies can be recognized if preceded by a title or a melody cue (an unscrambled version). Here melody cues preceded unfamiliar tonal or atonal, scrambled or unscrambled test melodies. Unscrambled repetitions of tonal melodies were easier to recognize than atonal ones for all subjects. Even inexperienced subjects encoded scale steps of tonal cue melodies more effectively than they encoded pitches of atonal cue melodies. Musically experienced (but not inexperienced) subjects found tonal scrambled melodies easier to recognize than atonal. Subjects apparently tested encoded cue patterns against chromas of comparison melodies. Experienced subjects used that information more effectively to evaluate the chroma patterns of octave-scrambled melodies.