code:

(mute_volume -96.0)		
	Decibel reduction when instruments miss notes/fail out.
	Setting this to 0 will cause no muting when notes are missed, even with multitrack audio.
	Left over from Beatles Rock Band (to hide artifacts of stem isolation). Still works.
	Default -96.0

(mute_volume_vocals -12.0)	
	Decibel reduction of the vocal track when the singer fails.
	Manually reducing the vocal track volume for play still has the default max value (-12.0)
	Setting this to 0 will keep the vocal track playing even if the singer fails.
	Either leftover from Beatles Rock Band (to hide artifacts of stem isolation) or older to
	limit the ability for people to rip "instrumentals".

(band_fail_cue xxx.cue)		
	Speculated: Changes sound effect played when the keyboardist (or band 
	with a keyboardist) fails a song, to match the voice of the instrument (piano, synth, etc.)
	Only currently spotted values are:
	"band_fail_electro_keys.cue"
	and
	"band_fail_vintage_keys.cue"
	Tested and does NOTHING! Probably unfinished feature.

(song_key x)			
	Overrides vocal_tonic_note value for displaying key of song in trainers.
	Indirectly confirms that vocal_tonic_note is used by trainers when displaying a song's key,
	and that's why song_tonality is written for songs with Pro Keys trainers.
	Since you can't enter trainers in customs this is totally useless!