gana (English spelling)

Japanese: gāna（英語表記）gana

…It is said that the Vedas were once divided into a thousand schools, but three schools remain as documents today. The collection, the Samhita, is divided into the ārcika, which contains only the lyrics of the hymns, and the gāna, which shows the melody with special symbols and the length and repetition of syllables that occur when singing. Most of the lyrics of the hymns themselves are taken from the Rig-Veda, and there are very few original ones. …

From [Buddhist Music]

The hymns are interspersed with syllables such as "ah" or "hai" and are sometimes repeated word by word. These songs are called gana and are currently handed down in three schools.
[Buddha and Music]
The Buddha himself did not engage in any musical activities.

*Some of the terminology that mentions "gāna" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…このベーダはかつて一千派に分かれていたと伝えられるが，現在は3派のものが文献として残っている。本集〈サンヒター〉は，賛歌の歌詞のみを収録した〈アールチカārcika〉と，特殊な符号で旋律を示し，かつ歌唱に際しておこる音節の長短，反復などを示した〈ガーナgāna〉とに分かれる。賛歌の歌詞そのものは《リグ･ベーダ》から採録したものがほとんどで，独自のものはきわめて少ない。…