Dirges and troubadours a very similar.
Dirges get an str agi group buff, troubs a sta agi buff
Dirges buff dps, troubs attack rate.
Dirges buff str and gives increased hate percentage to target for a concentration point, troubs lower the hate of all non fighters they are grouped with.
Dirges buff parry, troubs buff defense.
Dirges have a disease proc, troubs a AR proc.
Dirges give noxious mitigation, troubes arcane.
Dirges life tap, troubs mana tap.
Dirges get a fear, troubs a charm.
Those are what I think off the top of my head, another generallity is dirges buff more for melee characters while troubs buffs help casters more.
I would be better able to tell you the difference once the spell lists are updated. Right now they still use the old ones which are not updated for U13.
Edited, Mon Oct 3 17:11:09 2005 by dirges