Here are the results of my test last night:

Lv 40 song is a target dispel song. It takes out one buff per tick. The
debuff order seems to be from the most recently casted buff to the oldest
one. It removed my lv 49 wizard's damage shield, skin, and hp buff in 3
ticks. It couldn't remove his ultravision however. No text message, you
just see a purple lightball on target like the graphic effect of chain song.
It was never resisted the many times I tried it.

Chain song is fixed! No more spending 10 min chasing down a green SoWed
shaman!

Chain song on self will still break snare when the song effect is over.

Chain song on self will still break root, and when the song effect is over,
you move at normal rate.

The new DoT change applies to our songs as well. I tested the lv 48 CoC
song on 4 darkweed snakes. For two of them, I stand still and play the song
for one hit. Each time the snake would lose about 3/4 of its health after 3
ticks. The other 2 snakes, I play the song once and start to run away from
it. Each of those snake only lost about 1/2 hp after 3 ticks. So that is
33% decrease in damage as announced by Verant when the MOB is chasing
someone.

Our Pixie Strike song is faster than any Lv49 wizard DD spell. I can
interrupted my friend almost everytime. When hit, wizard spell damage never
hit me for max damage. Probably becuase of the patch.

Our songs has also been reduced in damage in PvP. Lv 48 song CoC (with lute)
only hit for about 100 damage in PvP. Before the patch, it hit for 150
damage in PvP.

Lv 48 CoC and Lv 2 CoD stacks. With a lute, at level 48, they did over 200
AE damage in 3 ticks.