Hitetsu,
Will this script continously run? Or will I have to hit the macro key every time it runs through the script?
It'll run continuously, though it's intended to be used as a "load as you need" spellcast. To finish it, you should be able to rest and it be good. I've not used it in a few years though, so I can't really remember :D
If it's still trying to cast songs after you've rested for a bit, then just //unload Spellcast or load a different file (//sc l filename)