Only Use the one that corresponds to what main menu music is playing, its advised to use only 1.
So if its the remixed main menu music, you would hold R before the stage loads, and you will get the music you so desire
The following are all decrypted, please use GCNcrypt to use them.
Also make sure you dont try to alter the music in anyway during gameplay, or the game freezes.
Music Modifiers
XXXX Digits
0004 - All Star Garden
0005 - Fire Emblem
0006 - Ice Climbers
0007 - Big Blue
000A - Peach's Castle
000E - Corneria
0011 - Dr Mario Theme
002D - Flatzone
002E - Fourside
006C - Kongo Jungle
00A8 - Great Bay
00AA - Green Greens
00AE - How To Play
00AF - Battlefield II
00B0 - Final Destination Remix
00B2 - Icicle Mountain
00B3 - Mushroom Kingdom
00B4 - Mushroom Kingdom (Finale)
00B5 - Mushroom Kingdom II
00B6 - Mushroom Kingdom II (Finale)
00F3 - Starman
00F4 - Fountain of Dreams
00F8 - Jungle Japes
00FB - Brinstar Depths
0102 - Main Menu
0103 - Grab a trophy
0104 - Main Menu 2
0107 - Balloon Fighter
0108 - Mute City
0110 - Jungle Japes N64
0111 - Dreamland
0112 - Yoshi's Island N64
0114 - Onett
0115 - Onett Remix
011B - Poke'Mon Remix
011C - Poke'Mon Stadium
011F - Poke' Floats
0121 - Rainbow Ride
0123 - Lost Woods
0124 - Hyrule
0125 - Warning Siren
0126 - SMB3 Remix
0161 - Final Destination
0162 - Giga Bowser Battle
0163 - Metal Battle
0164 - Battlefield
016D - Break the Targets!
01E0 - Venom
01EC - Yoshi's Island
01EE - Yoshi's Story
01EF - Brinstar