Interpreting the Haunting Melody feat

[jasonzehrung]

I'm currently playing a bard and found the fear thread on the old boards:

http://brilliantgameologists.com/boards/index.php?topic=3809.0

The interpretation of the Haunting Melody feat that Caedrus uses is generous to say the least.  The way I read it is you may use any perform skill to cause the effect as a standard action; the way Caedrus interprets it is that it can be activated a free action whenever you use another bardic music ability.  Are there any rulings clarifying this?  What are others opinions on it?

Thanks,
Jason