Enharmonic pitch - enharmonic pitch

…(2) In modern theory, the relationship between the same notes even if the note names and notation are different, such as the approximate minute intervals in just intonation, and the 12-tone equal temperament, such as B sharp and C, or C sharp and D flat on the keyboard, is called enharmonic. Enharmonic intervals are intervals that are differently notated but are the same in equal temperament, such as a diminished fifth and an augmented fourth, or a minor third and an augmented second. In this way, calling a note by a different name (enharmonic conversion) or reinterpreting a chord as a different kind of chord (enharmonic transposition) is an important means of modulation, and this type of modulation is called enharmonic modulation. …

*Some of the terminology explanations that refer to "enharmonic intervals" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…(2)近代理論においては，純正律における近似的な微小音程，12平均律では，たとえば鍵盤上の〈嬰ロ〉と〈ハ〉，〈嬰ハ〉と〈変ニ〉のように，音名と記譜法が異なっても同一の音の関係をエンハーモニック(異名同音)と呼ぶ。また異名同音的音程とは，減5度と増4度，短3度と増2度のように，記譜上は異なっても平均律上では同じ音程をなす音程である。このように異名同音的に，ある音を別の名で呼びかえたり(異名同音的転換)，ある和音を別種の和音として解釈し直したりすること(異名同音的転義)は，転調の重要な手段の一つであり，このような転調を異名同音的転調という。…

※「異名同音的音程」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報