Currently working on a Firered Rom Hack where you can get to some parts in Hoenn. But I´m struggling to insert R/S/E Music (Like Battle Themes, Route Themes etc) via Sappy, some sounds just mukty. I heard about a Black and White Music Patch for FR/LG, is something similiar existing with R/S/E sounds for Firered/Leafgreen. Like a .ips file or something?
There doesn't seem to be an RSE patch for FR. But all RSE instruments are included in FR (some hidden), so you can just create blank voicegroups, locate the instrument offsets, copy the ADSR information from the RSE ROM (important, or the music might sound too loud or too low), and finally port the tracks into the target FR ROM.
You are challenged by Pokémon Trainers Red, Blue & Leaf!
Pokémon AgateRed and JadeGreen (Chapter 1 Finished, Chapter 2 In Progress)
My remixed music list: Here
My deviantART page: Here