Even if it was a difficult operation to copy a song, it only takes one person to do it. After that the spread of the song via the Internet or other means of propagation is only limited by the honesty of the users.

青竹 云海 晨光 星夜 荷风 晴雪 秋山 听海 沙丘 森语 梅影 花野 听雨 晴窗 暮色 橘光