Noob question about motion and sound

Hi,
I had a simple question that i couldn't answer through searches. I was just wondering is someone could point me towards some info on using a motion sensor and arduino to play back music when the sensor is activated.
I know this is lame question but I am utterly new to the arduino and I am doing it for a project at work.
Thanks for any help.

Break the problem down into its component parts:

  1. detect when motion sensor is triggered
  2. play some music.

There are examples for both (or very, very close) in the tutorials and playground.

thanks alot for the help, is it possible to upload a short soundtrack to an arduino that it can then output to s set of speakers?

is it possible to upload a short soundtrack to an arduino that it can then output to s set of speakers

If by "soundtrack" you mean "sample", not really, no, unless you use some form of external memory like an SD card - the AVR processor simply doesn't have sufficient memory.

What you need is an arduino and a wave shield, the arduino does the switching, the shield plays the audio

As has been said, the Arduino lacks enough resources to do it alone.