The major second is a term for "interval" in music theory. In the diatonic scale, two adjacent tones are whole steps and semitones, and the whole tone here is the major second. A major second is a whole-tone relationship between two tones, such as 12, 23, 45, 56, and 67 in a diatonic scale.

In music theory, minor second is a term for "interval" and is a type of interval. In the staff, two adjacent notes form a second interval. But the difference between two adjacent tones may be a whole tone or a semitone. Here, the interval that differs by one semitone is the minor second. Such as 34, 71 in a diatonic scale. Extended information

The difference between major second and minor second:

If there is a whole step between the two notes, it is a major second, and if there is a semitone interval, it is a minor second. . Calculation of the interval relationship between two tones: count in ascending order of the diatonic scale, including the tones at both ends.

For example, 1-3 (including three tones 1, 2, and 3) is a third, among which 1-2 is a whole tone, and 2-3 is also a whole tone, then 1-3 contains Two whole tones are added, which is a major third. 2-4 is also a third, but 2-3 is a whole tone and 3-4 is a semitone. That is, 2-4 contains a whole tone and a semitone, which is the minor third.

1-7 (including the seven tones 1, 2, 3, 4, 5, 6, and 7) is the seventh. 2-6 includes the five tones 2, 3, 4, 5, and 6) is the fifth. And so on.

How to memorize major second and minor second:

The bass is lowered, or the treble is raised, and the interval is increased.

The bass is raised, or the treble is lowered, and the intervals are reduced.

The arrangement of the major and minor intervals (from small to large, increasing by semitones):

Pure one, minor two, major two, minor three, major three, pure four, augmented four = Minus five, pure five, minor six, major six, minor seven, major seven, pure eight.

Special note: #3=4, but 2#3 and 24 are not the same interval, because 23 is the second degree and 24 is the third degree, and the degree cannot be changed! It can

be resized.

About the increase and decrease of intervals:

An interval that is a semitone smaller than a pure interval is a diminished interval, such as: 3b4, 34 is a minor second, and 3b4 is a diminished second.

An interval that is a semitone larger than a pure interval is an augmented interval, such as: 1#2, 12 is a major second, and 1#2 is an augmented second.

Reference materials: Baidu Encyclopedia - Major Second Degree

Baidu Encyclopedia - Minor Second Degree

Baidu Encyclopedia - Musical Interval