自然音阶 meaning in English

major diatonic scale
scale of just temperament
scale, diatonic

Diatonic seventh chords use the notes of the diatonic scale to add a seventh above the root to triads
自然七和弦使用自然音阶的音，在三和弦上增加根音之上的七音。
The first degree of the diatonic scale is the tonic , the second the supertonic , the third the mediant , the fourth the subdominant , the fifth the dominant , the sixth the submediant , the seventh the leading tone or leading note
自然音阶的第一级为主音，第二级为上主音，第三级为中音，第四级为下属音，第五级为属音，第六级为下中音，第七级为导音。
The intervals of a fourth , fifth and octave in the diatonic scale are described as perfect intervals , as are the wider intervals above the octave , such as the eleventh or twelfth , other wise known as the compound perfect fourth and compound perfect fifth
自然音阶的四度、五度和八度音程为纯音程，高于八度的更大音程诸如十一或十二音程称为复合纯四度和复合纯五度。