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.
(2.2) Intervals of the Major Scale. The Major scale is by far the most common scale in western music. When played in sequence, the notes of the Major scale make the famous do-re-mi-fa-so-la-ti-do sound. This characteristic sound of the Major scale is created by the pattern of intervals between its notes. There are seven notes in the Major scale and seven intervals between them. This pattern is: When this pattern is used to extract notes from the Chromatic scale, we arrive at the Major scale. Adding the semitone interval sizes together (2+2+1+2+2+2+1) gives a total of 12, the number of semitones in a octave. This is also true for every other (non-Major) scale type.