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.
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.
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.