DIAO, fourth tone. This word comes from the "tone" of the music score (tiao is pronounced as a verb, only diao is pronounced as a noun), and the three stages of perfume (perfume pyramid structure), also called top fragrance, base fragrance, and bottom fragrance. The three stages of perfume are like a piece of music, with intro, interlude and ending.

Top notes and top notes (prelude): give people the first impression, which is short-lived, impactful, and attractive, making people continue to listen.

Middle note, base note (interlude): the theme and core of the perfume, which lasts for a long time, connects to the top note, and is experienced repeatedly.

Tail notes, base notes (outro): restrained ending, not as prominent as the front and middle notes (in fact, the tail notes of the perfume are present throughout the whole process, just because the front and middle notes are more prominent, and the tail notes are more prominent. The fragrance will not be obvious during the whole process, until the end of the front and middle notes, the base notes will rise), followed by the middle notes, the "resounding sound" of the perfume, slowly fades and diffuses over time until it completely disappears in the air.

The word "tiao" here means "tune", which means "musical changes in height and length", rather than "harmony", which means "mixed action behavior".

There is a term in perfume called diao, which refers to the theme style of fragrance. For example, floral fragrance is based on floral fragrance; wooden fragrance is mainly based on wooden smell; aquatic fragrance is based on the smell of wood. The tone is to give people a feeling of water vapor or sea breeze. This is just like there are G keys and F keys in music, which are names with one or a few notes as the main tone. They are collectively called "mode" (diao). In perfume, it's called a note.