I can only think of BoH that has an insta-cast song click.
For song-proc, again I can only think of :
http://wiki.project1999.com/Harmonic_Spear
Otherwise, from memory, you have to go way in the future to find a useful insta-click song item, the PoWater lute:
http://everquest.allakhazam.com/db/item.html?item=18072
cheers,
Astuce