I did a music pack on Rockman Gray Zone, (http://www.mediafire.com/?y8sseln6hfph4y8) which has some pretty awesome songs. Just want to note that they are all OGG files, not MUS files, in case that's important to anyone.
There's the link^in case you didn't notice it was blue and everything else wasn't...
Here's a command list to choose the music you want to listen to. For those who don't know how to change music, open up the console and type "changemus XXXXX", XXXXX being the corresponding code shown below for the music you want. As an added bonus, if I know where a song is from, I'll tell you. Ya I know, I'm a nice guy ;)
RGZAIR - Airman's Stage (Flame Mammoth from Megaman X)
RGZBOS - Boss Battle
RGZBUB - Bubbleman's Stage
RGZCRA - Crashman's Stage
RGZCRE - Credits
RGZDW1 - Dr. Wily's Fortress Stage 1
RGZDW2 - Dr. Wily's Fortress Stage 2 (Jet Stingray from Megaman X4)
RGZDW3 - Dr. Wily's Fortress Stage 3
RGZDW4 - Dr. Wily's Fortress Stage 4 & 5
RGZDW5 - Dr. Wily's Fortress Final Stage
RGZEND - Ending (Wiping Tears from Megaman Battle Network 3)
RGZFLA - Flashman's Stage
RGZGET - Weapon Get! (Proof of Courage from Megaman Battle Network 3)
RGZHEA - Heatman's Stage (Rainbow Road from Mario Kart 64)
RGZINT - Title Screen
RGZMET - Metalman's Stage
RGZQUI - Quickman's Stage (Overdrive Ostrich from Megaman X2)
RGZSEL - Stage Select
RGZW2B - Wily's Fortress Boss 2 (Great Battlers from Megaman Battle Network 3)
RGZWFB - Final Boss (Zero's Theme from Megaman X2)
RGZWINT - Wily Fortress Intro
RGZWOO - Woodman's Stage (Wire Sponge from Megaman X2)