妙法蓮華經文句 2.129

2.129

四乾闥婆，此云嗅香，以香為食，亦云香陰，其身出香，此是天帝俗樂之神也。樂者幢倒伎也，樂音者，鼓節弦管也，美者幢倒中勝品者，美音者弦管中勝者也。

The four gandharvas, translated here as "scent-smellers", feed on fragrance; they are also called "fragrant aggregates" because their bodies emit fragrance. These are the devendra's spirits of worldly music. Music refers to acrobatic performances with inverted banners; musical sound refers to drums, rhythms, strings, and pipes; beautiful refers to the superior class among banner acrobatics; beautiful sound refers to the superior among strings and pipes.