This article is from the CD-Recordable FAQ, by Andy McFadden (email@example.com) with numerous contributions by others.
You are allowed to make an archival backup of software, but the same
doesn't necessarily hold true for music. The Home Rights Recording Act
will allow you to duplicate music under certain circumstances.
A discussion of the topic, including details on past and pending
legislation, can be found on the Home Recording Rights Coalition web site
at http://www.hrrc.org/. The text of the Home Rights Recording Act can
also be found here.
The Recording Industry Association of America, which represents the music
industry, has a web site at http://www.riaa.com/.
An article entitled, "Copying Music to CD: The Right, the Wrong, and the
Law" was at http://www.emediapro.com/EM1998/starrett2.html. It can still
be found through the web archive here:
http://www.brouhaha.com/~eric/bad_laws/dat_tax.html has some relevant
information and pointers.
http://www.bmi.com/ and http://www.ascap.com/ have yet more perspectives