Despite the remarkable variability music displays across cultures, certain recurrent musical features motivate the hypothesis that fundamental cognitive principles constrain the way music is produced. One such feature concerns the structure of musical scales. The vast majority of musical cultures use scales that are not uniformly symmetric—that is, scales that contain notes spread unevenly across the octave. Here we present evidence that the structure of musical scales has a substantial impact on how listeners learn new musical systems. Three experiments were conducted to test the hypothesis that nonuniformity facilitates the processing of melodies. Novel melodic stimuli were composed based on artificial grammars using scales with different levels of symmetry. Experiment 1 tested the acquisition of tonal hierarchies and melodic regularities on three different 12-tone equal-tempered scales using a finite-state grammar. Experiments 2 and 3 used more flexible Markov-chain grammars and were designed to generalize the effect to 14-tone and 16-tone equal-tempered scales. The results showed that performance was significantly enhanced by scale structures that specified the tonal space by providing unique intervallic relations between notes. These results suggest that the learning of novel musical systems is modulated by the symmetry of scales, which in turn may explain the prevalence of nonuniform scales across musical cultures.

尽管音乐在不同文化中表现出显着的可变性，但某些反复出现的音乐特征激发了这样一种假设，即基本认知原则限制了音乐的产生方式。其中一个特征涉及音阶的结构。绝大多数音乐文化使用非均匀对称的音阶，即包含音符的音阶在八度音阶上分布不均。在这里，我们提出证据表明音阶结构对听众如何学习新的音乐系统有重大影响。进行了三个实验来检验不均匀性有助于旋律处理的假设。新颖的旋律刺激是基于使用具有不同对称水平的音阶的人工语法组成的。实验 1 使用有限状态语法在三个不同的 12 音等律音阶上测试了音调层次和旋律规律的获取。实验 2 和 3 使用更灵活的马尔可夫链语法，旨在将效果推广到 14 音和 16 音等律音阶。结果表明，通过提供音符之间独特的音程关系来指定音调空间的音阶结构显着提高了性能。这些结果表明，新音乐系统的学习受到音阶对称性的调节，这反过来又可以解释音乐文化中不均匀音阶的普遍存在。实验 2 和 3 使用更灵活的马尔可夫链语法，旨在将效果推广到 14 音和 16 音等律音阶。结果表明，通过提供音符之间独特的音程关系来指定音调空间的音阶结构显着提高了性能。这些结果表明，新音乐系统的学习受到音阶对称性的调节，这反过来又可以解释音乐文化中不均匀音阶的普遍存在。实验 2 和 3 使用更灵活的马尔可夫链语法，旨在将效果推广到 14 音和 16 音等律音阶。结果表明，通过提供音符之间独特的音程关系来指定音调空间的音阶结构显着提高了性能。这些结果表明，新音乐系统的学习受到音阶对称性的调节，这反过来又可以解释音乐文化中不均匀音阶的普遍存在。