Мне снился звук, не слышанный никем

Аада, спасибо вам! * * * In music, the dominant (...) called the dominant because it is next in importance to the first scale degree, the tonic. The triad built on the dominant note is called the dominant chord (...) dominant function, which means that it creates an instability that requires the tonic for resolution. Music which modulates (changes key) often modulates to the dominant key. Modulation to the dominant often creates a sense of increased tension; as opposed to modulation to the subdominant (...) which creates a sense of musical relaxation. https://en.wikipedia.org/wiki/Dominant_(music)

Виктор, спасибо вам!