TO convert several hundred DRM encoded songs and to strip the DRM protection off, what I suggest is SoundTaxi Professional Napster to iPod converter. It converts DRM protected music files and various audio files to desired output for use with iPod, MP3 player, mobile phone or PC or any device. Converted songs have NO DRM restriction anymore. It is Super fast in conversion, and the playback speed is about 50x.

You can download the free trial from http://www.thevideolife.com/napster-to-ipod-itunes.html