There are two types of CDG files that contain vocals:
1. True MULTIPLEX songs where only music is on the left (normally) channel and music + vocals on the right. The Vocal-L/R buttons will remove these vocals. The music is MONAURAL.
2. Other songs exist where the music AND vocals are stereo, and the vocals are mixed on both the right and left channels. There is no way to remove the vocals in these songs as they are on both tracks. The music is STEREO.
Usually #2 songs are from discs titled "4+4" or "8+8" indicating that 4/8 of the songs are without vocals, and 4/8 are with vocals.
A test for #2 files is to listen to what instruments you hear when you click Vocal-L, and then click Vocal-R and see if there are DIFFERENT instruments now playing. If so, this proves it is a true stereo song, and probably has the vocals mixed on both tracks.
