Everything turn off when I unplugged the USB cable (Arduino+ music maker Shield)

When I unplug the USB cable to Arduino Uno,music stop playing like he doesn't keep the sketch in memory...everything turns off.

Still powered by 5v DC...But no led "ON" on the board!

I downloaded the sketch and save it.

Somebody has an answer

Eric-Roobaert: Still powered by 5v DC...

Into where? RTM where it says:

The board can be supplied with power either from the DC power jack (7 - 12V), the USB connector (5V), or the VIN pin of the board (7-12V). Supplying voltage via the 5V or 3.3V pins bypasses the regulator, and can damage your board. We don't advise it.

Thank found the problem. need 9vdc!