The simple answer is that he needs a Whole House Audio Controller. You can get them to handle 2, 4, 6, or even 12 zones. Some are a receiver type (built-in amps) so you can hook them directly to the speaker wire and others are a multi-zone pre-amp type that require separate amps for the speakers. There are cases such as long wire runs or harder to drive speakers that may require the separate amp.
Like most audio products, prices (and quality) can vary widely. Your local Alarm/Wiring/AV System installer should be able to install something that works well for background music. One word of caution is that most of these companies have no idea what good sound is (most started as wire pullers for house alarms but realized there was more money to be made on installing speaker wire and speakers). For more critical listening areas, check out some of the better High-End Audio dealers in the DFW area (or my demo room if you are ever in the Austin area).
Best of luck.
Julian
www.sedonaskysound.com
