Music is divided into major and minor tones. The so-called major is the most common high-pitched 1do expressed by scales, and the so-called major triad is expressed by chords. For example, C major is 1+3+5(do+mi+so).

The so-called minor is to change one or two notes on the basis of the major. The scale of the minor is 1do 2re down 3mi 4fa 5so down 6la 7xi high-pitched 1do, and it is the so-called minor chord when expressed by chords. For example, C minor is 1+ 3+5(do+ mi+so).

by the way, flat is half a degree, which is indicated by b (except for the difference of half a degree between 3-4 and 7-1 in major scales, the other two adjacent notes are all one degree), and half a degree is indicated by #.

this may not be straightforward enough. Generally, the colors in major are bright and firm, while those in minor are soft and dim. It is emphasized that there is no obvious boundary between major and minor, and a piece of music will often change from major to minor, and as a whole, it will be biased towards one side. Example:

In today's pop music, songs with a big key account for the majority. I think it may be easier to write in major, and most people prefer bright colors, such as Taylor swift's songs and fearless. Westlife's incomparable classic songs seasons in the sun. There are too many major pop songs in China, so I won't give examples.

watch the minor again. The more famous Casablanca, and the theme song my heart will go on of Titanic, Guang Liang has a song "I want to go somewhere", which is preceded by minor and changed to major at the climax. A lot of rock music is minor.

Actually, there is a way to distinguish between major and minor tones, that is, to see whether a melody falls on major triad or minor chord at the end.

explain the meaning of "1=C 2/4" again. This is a symbol that only exists in the notation. "1=C" means that 1 in the notation means do in the key of C. More bluntly, this piece is in the key of C. If it is written as 1=D, it means that this piece is in the key of D.. 2/4 means that the music is 2/4 beats, the former 2 means that there are two beats per bar, and the latter 4 means that the quarter note is taken as a beat. What is a quarter note? A number in the notation has no horizontal line behind it and no horizontal line below it, so it is a quarter note. Other beats are 4/4, 3/4, 3/8, 6/8, etc.