Here is a bit of advise from a relatively low level
bard (lvl 22):

I use Denon's Discord and Chords of Dissonance a lot!
I twist them quite often. I know that the area
effect is an issue, but in places like Mistmoore it
isn't really a problem. Most of the time you get an
initiate or pledge another comes with it. So you are
fighting more than one at a time, so why not do damage
to all of them at the same time. It also helps out
parties around me.

When I lure, I use Bellow and then ofcourse Selo to
get the creature to my party. Once I get it back to
the party, I turn on Denon's and after the first pulse
I go for Chords and then 2 Bellows or a Bellow and
Anthem. This gives me almost 4 songs going at the
same time, with damage and buff. All the while I am
doing this, I am also meleeing. I know this sounds
complicated, but the amount of damage I can do is
staggering. Of course having a well balanced party
helps the eventual finishing off, but the 2 area
effect damage songs are quite good.

I don't know any of the exact numbers as to how much
damage the 2 songs do, but I can see the health bar of
the creature actually move every time it pulses.

Sedaien Reyvon