tonic key

1. A tonal system consisting of seven tones in fixed relationship to a tonic, having a characteristic key signature and being since the Renaissance the structural foundation of the bulk of Western music; tonality.
   调、主音包括七个与主音有固定关系的音色的调音系统，有独特的调号，自文艺复兴以来一直是西方音乐主体的结构基础；调性。

noun

1. the basic key in which a piece of music is written

   Synonym:    home key