Entropy in the Development of Tonality

In physics, according to the Second Law of ThermodynamicsSecond Law of Thermodynamics, the total entropyEntropy of a closed system either always increases or remains constant, it can never decrease. According to Claude Shannon’s information theoryInformation theory, ‘the system reaches its death when it contains as much information as it can handle’ (Vedral 2018, p. 58), so no new information can be stored in it. Here an analogy with the development of tonality can be found. In the classical or traditional sense tonality was a system with its own laws of regulating interrelations between musical intervals. From the end of the era of baroque and until the very beginning of the twentieth century tonality used to extend to become the main driving force behind the laws of composition regulating relationship between not only the intervals but also influencing all other parameters of music as well. Tonality was the dominant system that used to form the framework of a harmony. Indeed, tonality was actually harmony, or, to say better, tonality is a system for embodying harmony. Nevertheless, according to the opinions of numerous composers and scholars, at the end of the nineteenth century the situation in the world of classical music was such that there could no longer be any single new and/or fresh melody that would not repeat something that already exists. Anything (any melodic or harmonic element) within classical tonal system would inevitably resemble something already existing, and would appear as merely new embodiments of already existing combinations of sounds. Speaking in terms of entropy, the system reached its maximum capacity of handling new information.