Much of Western classical music relies on instruments based on acoustic resonance, which produce harmonic or quasi-harmonic sounds. In contrast, since the mid-twentieth century, popular music has increasingly been produced in recording studios, where it is not bound by the constraints of harmonic sounds. In this study, we use modified MPEG-7 features to explore and characterise the evolution of noise and inharmonicity in popular music since 1961. We place this evolution in the context of other broad categories of music, including Western classical piano music, orchestral music, and musique concr\`ete. We introduce new features that distinguish between inharmonicity caused by noise and that resulting from interactions between discrete partials. Our analysis reveals that the history of popular music since 1961 can be divided into three phases. From 1961 to 1972, inharmonicity in popular music, initially only slightly higher than in orchestral music, increased significantly. Between 1972 and 1986, this rise in inharmonicity was accompanied by an increase in noise, but since 1986, both inharmonicity and noise have moderately decreased. In recent years (up to 2020), popular music has remained much more inharmonic than popular music from the 1960s or orchestral music involving acoustic resonance instruments. However, it has become less noisy, with noise levels comparable to those of orchestral music. We relate these trends to the evolution of music production techniques. In particular, the use of multi-tracking may explain the higher inharmonicity in popular music compared to orchestral music. We illustrate these trends with analyses of key artists and tracks.

翻译：西方古典音乐大多依赖于基于声学共振的乐器，这些乐器产生谐波或准谐波声音。相比之下，自二十世纪中叶以来，流行音乐越来越多地在录音室中制作，不受谐波声音的限制。在本研究中，我们使用改进的MPEG-7特征来探索和表征自1961年以来流行音乐中噪声与不和谐性的演变。我们将这一演变置于其他广泛音乐类别的背景下，包括西方古典钢琴音乐、管弦乐和具体音乐。我们引入了新的特征，以区分由噪声引起的不和谐性与由离散分音间相互作用产生的不和谐性。我们的分析表明，自1961年以来的流行音乐历史可分为三个阶段。从1961年到1972年，流行音乐中的不和谐性从最初仅略高于管弦乐，显著增加。1972年至1986年间，不和谐性的上升伴随着噪声的增加，但自1986年以来，不和谐性和噪声均适度下降。近年来（截至2020年），流行音乐的不和谐性仍远高于1960年代的流行音乐或涉及声学共振乐器的管弦乐。然而，其噪声水平已降低，与管弦乐相当。我们将这些趋势与音乐制作技术的演变联系起来。特别是，多轨录音的使用可能解释了流行音乐相比管弦乐更高的不和谐性。我们通过对关键艺术家和曲目的分析来阐释这些趋势。