That's really simple, tear the code appart and you discover that variable CounterA is a pointer into EEPROM starting at Address location 1 (for the first line)...

CounterA=1

Then after each note is played, we increment it by four...

CounterA=CounterA+4

So CounterA is pointing to the note currently being played... simply do something like this...

Code:
MusicalLoop:		
	If CounterA=1 then LCDOut $FE,1,"Yankee Doodle"
	If CounterA=17 then LCDOut $FE,$C0,"went to town"
	If CounterA=33 then LCDOut $FE,1,"A-riding on",$FE,$C0," a pony"
	If CounterA=57 then LCDOut $FE,1,"Stuck a feather"
	If CounterA=73 then LCDOut $FE,$C0," in his hat"
	If CounterA=85 then LCDOut $FE,1,"And called it",$FE,$C0," macaroni.
	Read CounterA,NotePeriod.Highbyte
	If NotePeriod.Highbyte=$FF then
		LCDOut $FE,1
		Pause 2000
		Goto RestartLoop
		endif
	Read CounterA+1,NotePeriod.Lowbyte
	Read CounterA+2,CounterB
	NoteRepeat=CounterB*10
	Read CounterA+3,CounterB
	MessagePrompt=MessagePrompt+1
	NotePause=CounterB*10
	CounterA=CounterA+4
	MessageNote
	Gosub PlayNote
	Goto MusicalLoop
Only on this forum... rocket science for 5-year-olds (by five year olds!!).

If you want to go more advanced... you can have the words appearing prior to every note...

Code:
	If CounterA=1 then LCDOut $FE,1,"Yan"
	If CounterA=5 then LCDOut "kee "
	If CounterA=9 then LCDOut "Doo"
	If CounterA=13 then LCDOut "dle"
	If CounterA=17 then LCDOut $FE,$C0,"went "
	If CounterA=21 then LCDOut "to "
	If CounterA=25 then LCDOut "town"
etc etc