For example, in a woman with a 21-day cycle, the follicular phase is likely seven days; in a woman with a 35-day cycle, the follicular phase is likely twenty-one days. (Note: It is possible for a luteal phase defect to shorten the length of the menstrual cycle â this will be discussed in a future article on Phase II.
The diatonic scales. The diatonic scale is most familiar as the major scale or the natural minor scale (or aeolian mode). The diatonic scale is a very important scale. Out of all the possible seven note scales it has the highest number of consonant intervals, and the greatest number of major and minor triads.he diatonic scale is a very important scale. Out of all the possible seven note scales it has the highest number of consonant intervals, and the greatest number of major and minor triads.
Also called tonality. any of the 24 major and minor diatonic scales considered as a corpus of notes upon which a piece of music draws for its tonal framework. 1  the main tonal centre in an extended composition: a symphony in the key of F major. 2  the tonic of a major or minor scale. 3  See tuning key.