According to the Recording Industry Association of America, copying music to an analog cassette or an audio CD-R is permissible for personal use only. Copying music in order to sell it or even just to lend to a friend is considered illegal.
Copyright laws are designed to protect artists from having their work copied and used without their permission. Since purchasing music online has become increasingly popular, users may want to burn a copy of the music to a disc to listen to the songs on a CD player in their home or in their vehicle. Some may even burn a copy of a physical CD they purchased in order to preserve the original disc and packaging. So long as the music was originally purchased legally and the copies are not being sold or distributed without the permission of the own, making copies of music is legal.