Not only is it not in game, but it is NOT a kunark song, it was added 3 months into velious during a famous patch intended to balance some classes:
http://www.tski.co.jp/baldio/patch/20010221a.html
Bards:
* Added new level 20 Bard Song: Cassindra`s Chant of Clarity.
* Bards defensive skill made exactly the same as a warriors.
* Changed it so that the bard spell Denon's Desperate Dirge to increase damage by 10pts per level over 45. Also made it so the spell does 20% more damage using the Puretone discipline.
cheers!