2 Day Birthday Stormtrooper Xbox Project!, Getting sound to play durring boot with greeting card pcb Options

[crusty_punk]

My best friends birthday is day after tomorrow. He is a Star Wars fanatic! His Fiance is going to buy him the r2d2 360 for him as a wedding gift, but that's several months away....

In the mean time I want to build him an original xbox themed to "Stormtrooper".
So far I have the xbox, the TSOP is already flashed, The jewel is already cleared and ready to paint, I'm going to start masking off the "X" to paint, etc... yadda yadda yadda. hard drive is ready, led's, controller blah blah blah....

The thing that I want to do to make this xbox stand out from the rest is... I want it to play the Star Wars theme when it turns on. I went and bough a "singing" star wars greeting card that's perfect. I gutted the card and now I'm looking at a small PCB, 2 1.5v watch batteries and a speaker. I know the mechanics of how the card works, but I'm trying to figure out how to make it trip when the xbox is powered on.

I would like to remove the batteries and use a 3v line from the xbox... I know where that is... so I have the power mapped but I was wondering how to trip it. Can I solder leads to the "spring" and the pad and attach them to ground points on the motherboard?

Has anyone else ever done this?
What was your method?

inb4: set XBMC to play it at start up
I have already told the bios' to not display the flubber or sound etc.. I want it to start playing as soon as the power button is pressed and it should be done by the time the xbox is completely booted.

Thanks in advance!
-Josh

P.S. I am taking pictures as I go and when I'm done I'll show you guys. I don't want to post anything right now because I think he slinks around here once in a while...