For a lot of spell changes, Lucy is an invaluable source. In the case of this song, here is the change recorder in mana cost:
04 Sept 2004: Change mana cost fom 20 to 60
Source:
http://lucy.allakhazam.com/spellhist...50&source=Live
The only thing I'm not sure of but mauybe someone would have an idea: do the date of changes indicated follow the Live timeframe or were they late? If so, how late were they?
Nagash/Petitpas