Nothing is more frustrating than your iPod Shuffle freezing mid-song when you are exercising or traveling. In most cases, the device can be reset without losing any of your data, much like “rebooting” your computer.
Disconnect your iPod Shuffle from your computer if it is connected. If it froze during an iTunes action, "eject" it from iTunes first.
Turn the device back on. Place the device in the "Play" or "Shuffle" mode.