MP3 shield and motion sensor

I had been able to create simple MP3 player with music shield

http://www.maplin.co.uk/p/music-shield-for-arduino-n99dg

however I would like to control it by motion sensor.
Can you point me if I need to buy anything else or somehow I can use above music shield and connect it to motion sensor. Problem which I have is lack of pins because shield it's covering all of them.

Can you point me if I need to buy anything else

Well you need a motion sensor.

Problem which I have is lack of pins because shield it's covering all of them.

You can solder wires onto the top of the unused pins sticking through the board.

Hi Grumpy_Mike,
Thank you for your reply, I have motion sensor

however I don't know to which pins I need to connect

http://postimg.org/image/4bhbmc4wx/

Connect it like this picture


That is power +5V on the left signal in the middle and ground right.
The signal is connected to any Arduino pin but avoid pins 0 & 1 as they are used for serial data.

Grumpy_Mike,
I'm able to connect motion sensor to Arduino without music shield.
I wonder which pin I can use on Music shield.

You can use any pin the music shield is not using. Look at the schematic of the music shield and see what pins it is using. If you are worried about physical access then just solder the wires direct onto the music shield.