First Download the latest beta of Road Runner, as it supports the new commands in the SD line. Just Download the Road Runner.exe and replace your with it.
Try these lines:
The second line SD shows *.* to show ALL file types. If you just want music use *.mp3Code:/, S, x, y, w, h, fore R;RGB, G, B, back R;RGB, G, B, folder R;RGB, G, B, file R;RGB, G, B, selected R;RGB, G, B, select R;RGB, G, B, trs, font pt;FONT, font name S01,114,110,575,262,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,0,0,0,TRUE,20,"Arial Narrow:B" /, SD, Alignment;Alignment, Disp;MODE, Icon Width, Icon Heigth, Path SD,00,01,50,50,"C:","*.*",1