Build servo driven rock-meter with mic input

This is a project Im starting. Its a real size foam guitar hanging on the wall, moving with the clock at increasing sound level.
I have not yet seen anything like this on the net. So if you have any ideas ,tips or information that could help the build, It would be greately appreciated.
I'm new to arduino programing, but have most of the examples up and running. My electronics experience is good.

I'm using the knob-servo example as servo source. But I need to lower the maximum servo speed. Do you have any idea how to do this?

This is the amplifier I'we planned to build. NerdKits - Piezoelectric Sound Meter
Do you have any experience with this solution? Should the amp output be diode rectified and capasitor smoothed?
Other device hacking ideas is also apreciated.

I'm using the knob-servo example as servo source. But I need to lower the maximum servo speed. Do you have any idea how to do this?

The maximum servo speed is based on the servo, and is not something that can be set in software. However, you can increase the delay between writing new values to the servo to increase the time it takes the servo to move through its entire range.

The speed of the servo with no load will be higher than when it has a load.

Have you mounted the foam guitar on the servo to see whether the servo can handle the mass?

It will be a thin foam board.

OK. I was picturing one of those foam "gloves" sold at baseball stadiums. More than an inch thick.

The thin foam board should not present a large enough mass to be a problem, but should present enough mass to slow the servo so it moves smoothly (though for the most part, that's up to you).