This is a pair convenience patches that allow Mog to learn Snowman Jazz in the World of Balance.
The first patch "Jazzy Narshe" makes the Narshe battle background associated with Snowman Jazz, and enemies can be encountered in the cliffs north of the town (the same enemies as in the passage to Arvis' house). Thus, players can fight a battle here with Mog in the World of Balance and learn Snowman Jazz.
The second patch "Jazzy Snowfield" adds enemies to the snowfields above Narshe in the World of Balance (the same enemies as in Jazzy Narshe) so Mog can learn Snowman Jazz there.
Both patches are for unheadered 1.0 roms, and can be used together or separately.
Database match: Final Fantasy III (USA)
Database: No-Intro: Super Nintendo Entertainment System (v. 20210222-050638)
File/ROM SHA-1: 4F37E4274AC3B2EA1BEDB08AA149D8FC5BB676E7
File/ROM CRC32: A27F1C7A