Can an iPod Shuffle 2nd gen usb cord work for a 4th gen iPod Shuffle?

No, an iPod Shuffle 2nd gen USB cord cannot work with a 4th gen iPod Shuffle. The 2nd generation Shuffle uses a different connector, while the 4th generation Shuffle employs a built-in clip with a specialized USB connector that is unique to that model. Therefore, you will need the appropriate USB cord designed specifically for the 4th generation iPod Shuffle.