"Transposition" refers to moving the entire music up or down from the original key to a new key in tonal music, while all the intervals, chords, marks, etc. of the melody remain unchanged. . What transposition changes is the pitch of the entire music, just like changing a song in the key of C to the key of D.

The method of transposing is mainly for staffs. In specific operations, the following three methods can be used: semitone transposition, interval transposition, and clef transposition. Each of these three methods has its own strengths and weaknesses, and you should decide which method to use based on actual needs.

Purpose of use: To make the music produce overall emotional color changes.