Musical improvisation, much like spontaneous speech, reveals intricate facets of the improviser's state of mind and emotional character. However, the specific musical components that reveal such individuality remain largely unexplored. Within the framework of brain's statistical learning and predictive processing, this study examined the temporal dynamics of uncertainty and surprise (prediction error) in a piece of musical improvisation. This study employed the HBSL model to analyze a corpus of 456 Jazz improvisations, spanning 1905 to 2009, from 78 distinct Jazz musicians. The results indicated distinctive temporal patterns of surprise and uncertainty, especially in pitch and pitch-rhythm sequences, revealing era-specific features from the early 20th to the 21st centuries. Conversely, rhythm sequences exhibited a consistent degree of uncertainty across eras. Further, the acoustic properties remain unchanged across different periods. These findings highlight the importance of how temporal dynamics of surprise and uncertainty in improvisational music change over periods, profoundly influencing the distinctive methodologies artists adopt for improvisation in each era. Further, it is suggested that the development of improvisational music can be attributed to the brain's adaptive statistical learning mechanisms, which constantly refine internal models to mirror the cultural and emotional nuances of their respective epochs. This study unravels the evolutionary trajectory of improvisational music and highlights the nuanced shifts artists employ to resonate with the cultural and emotional landscapes of their times.

翻译：音乐即兴与自发语言类似，揭示了即兴者心理状态与情感特征的复杂层面。然而，哪些具体音乐成分能够彰显这种个体性仍鲜有探索。基于大脑统计学习与预测处理的框架，本研究考察了音乐即兴作品中不确定性与惊奇（预测误差）的时间动态。研究采用HBSL模型，分析了涵盖1905年至2009年、来自78位不同爵士乐手的456首爵士即兴作品语料库。结果表明，惊奇与不确定性具有独特的时间模式，尤其在音高与音高-节奏序列中，展现了从20世纪初至21世纪的时代特定特征。相反，节奏序列在不同时代间呈现出一致的不确定性程度。此外，声学属性在不同时期保持稳定。这些发现凸显了即兴音乐中惊奇与不确定性时间动态随时代变化的重要性，深刻影响了各时代艺术家所采用的特异性即兴创作方法。进一步而言，即兴音乐的发展可归因于大脑适应性统计学习机制，该机制持续修正内部模型，以反映其所属时代的文化与情感微妙之处。本研究揭示了即兴音乐的演化轨迹，并强调了艺术家为呼应其时代文化情感景观所采用的微妙转变。