Disco is basically going to reduce the skills of the creature you target with it. So when you're taming something and it's pelting you with spells and melee damage, the discordance is going to leave that beastie with less skill to use against you. It basically means the beast won't hurt you quite as much.
I mostly just lead tame, no honor or anything else. Beat the creature down to a sliver of health and then tame when it's slow and doing a bit less damage. Then try to invis myself as much as possible while I'm taming. The problem that arose with this tactic more recently came when creatures started healing themselves up again. Where you could beat a dragon up and it was going to stay low in health for a few minutes, now it's usually healing as you fight it. So in that situation you might want to use disco to pull a greater dragon down a bit before you tame it. But I wouldn't put disco on a template just to tame creatures easily, because you really can tame anything with just a straight lead tame. It's just something you can do if you happen to have a tamer bard at your disposal when you're taming a greater dragon.
The reason I added disco to my tamer was for PvM when I was wanting to hunt larger game with my smaller pets. I rarely use a greater dragon so disco helps me take on creatures that are quite strong for my smaller pets to handle. It does help you as a tamer as I explained above, and you can disco a pet while you're training some skills so they train more quickly. The obvious one being discording a cu sidhe so you can finish training the healing by simply casting on the pup while it's in disco. Rather than spending an unhealthy period of time among rotting corpses. So it has value for tamers specifically, but you need to consider its use in PvM as well as taming to see the real benefits of it.
I use disco along with provoke on a really cramped tamer template, so I have target and crowd control and a pet or two at my disposal. That's when I find it gets really crazy and fun, but a straight disco tamer is great to have too. But yeah, it's mostly about the PvM.
Wenchy
