"If the music is similar in 8 bars, it is considered plagiarism": The "8 bars" here refers to the continuity, not the total amount (such as repetition at the climax). In a piece of music, there may be a part of the melody that is exactly the same, especially in long pieces. This problem is more prominent. Therefore, discontinuous identical measures will not be considered plagiarism. But it is not absolute. It depends on this Whether some "suspicious" measures are in harmony with the melody of this song, and whether there is obvious plagiarism intention, etc. Because in law, intention is the essential element.

Because there are only a few notes in total, it is inevitable that inspiration will collide when arranging and composing, and it will sound similar. This is a normal phenomenon