Follicular and luteal phase lengths. â variability of menstrual cycle. attributable to follicular phase. â  Mean cycle length ranges from 27.3 to 30.1 days between ages 20 and 40 years, follicular. phase length is 13-15 days, and luteal phase length is less variable and averages. 13-14 days1-3.
Any sequence of seven successive natural notes, such as C-D-E-F-G-A-B, and any transposition thereof, is a diatonic scale. Piano keyboards are designed to play natural notes, and hence diatonic scales, with their white keys. A diatonic scale can be also described as two tetrachords separated by a whole tone.
n (music) a series of notes differing in pitch according to a specific scheme (usually within an octave) the entire scale of musical notes. a scale with eight notes in an octave; all but two are separated by whole tones. a 12-note scale including all the semitones of the octave. a musical scale with fewer than seven notes. a gapped scale with five notes; usually the fourth and seventh notes of the diatonic scale are omitted. any of various fixed orders of the various diatonic notes within an octave.