Ripping audio from a DVD

Once again, I find myself asking for technical help. Does anyone out there know how to rip audio from a DVD? I have some concert DVDs that I would like to convert some of the songs to mp3 format so I can take a copy with me everywhere I go. Is this possible without having to buy some software or download some questionable software that may or may not be spyware or adware and ruin my computer?