I use something similar to record music from Pandore and last.fm, it’s called audials tunebite and it basically records whatever you hear on your computer. so if you only play your Pandora playlist, this is what it will record; plus, it recognizes the song, names it and then if you need to, you can also convert the files to different formats (mp3, aac, m4a, flac, ogg, wav, wma etc.)
*Audials softawre is legal and complies with Copyright Laws, as long as you don't redistribute the recorded songs to other people. Copyright Laws state that " When recording or converting media, please do not redistribute it to other people.“ So you can rest assured to download and use this program.