Scott,
You can also download it for FREE at http://www.kazaa.com/
Download their software then type “Sonar” in the search box, you’ll get multiple results, select the version you like, download it and uninstall the Kazaa software.
The reason I am advising to uninstall: It’s a 2-way communications tool where you can see other people’s computer contents while they see yours. If you uninstall it immediately after downloading Sonar you’ll be safe.

N.B. If you have an old 486 with 500 MB HD you can dedicate it for all Kazaa downloads.

Maged