Materials.

Twelve pairs of melodies were composed like the example shown in Figure 1. All melodies had a length of two bars of four beats each, plus one beat. The two melodies of a pair had exactly the same rhythmic patterns. The twelve melodic pairs had the same global rhythmic pattern: The first three beats of the two first bars consisted of eighth and/or sixteenth notes, the fourth beats of the two first bars and the final beat were quarter notes, and the same rhythmic pattern was used for the two bars of each melody. The two melodies of a pair, in addition to having exactly the same rhythms, had almost the same tones. The two melodies of a pair differed only by one, possibly repeated, tone in the first bar. The serial position of this changed note was varied across melodic pairs from the second eighth note of the first beat to the fourth beat. This note change modified the tonal function of the two last tones (the fourth beat of the second bar and the last beat, which were always the same musical note): these two last tones were either the tonic (tonally expected) or the subdominant (less tonally expected). The two last tones, though being the same musical note on the score, had not always exactly the same pitch: the last tone was either in-tune (thus being strictly identical to the penultimate tone) or slightly mistuned (its pitch being lowered by 13 cents, a .75% deviation in frequency). Twelve melodic pairs were composed so that each of the twelve major keys were represented. The 12 melodic pairs (12 melodies ending on the tonic and 12 melodies ending on the subdominant) and the 2 pitch frequency conditions (in-tune or mistuned) resulted in a total of 48 experimental melodies. Sixteen shorter melodies, which also ended on tonic or subdominants tones, were constructed to familiarize participants with the task. These shorter melodies were one-and-a-half 4-beat bars long, with the last 2 beats being the repeated target tones (identical repetition or mistuned repetition). Eight additional example melodies, composed as the 48 experimental melodies, were also used to train participants. All the melodies were created in MIDI with Cubase SX2 software (Steinberg) and were transformed into audio files using The Grand (a VST piano instrument by Steinberg). MIDI velocity was constant for all pitches. Melodies were recorded at a tempo of 789.5 ms per beat without any expressive or stylistic timing variations. This tempo represents a duration of 789.5 ms for a quarter note, 394 ms for an eighth note, and 197 ms for a sixteenth note. The overall duration of a melody was 7600 ms (including instrumental resonance for the final target tone that increased its length). Cubase’s micro-tuner was used to create the melodies with the last tone lowered in pitch by 13 cents (a cent is 1/100 of a semitone in logarithmic units).

Figure 1. Example of the 12 pairs of melodies used in the present study. The tone differing between related and less-related melodies can be visually identified by the alteration marks.