Question: Why is it that "China Beach" has not come out on DVD? Is it a problem with the music used in the show?

Answer: According to published reports over the years, that is exactly the problem. (You may have seen sets for sale online, but they are bootlegs, and you run a lot of risks buying them.)

The series used large amounts of period music, and the music was an important part of the texture of the show. But rights for use on DVD would have to be acquired, and that can prove expensive.

Some shows have opted for DVD release without the original telecasts' music — "Tour of Duty," like "China Beach," a Vietnam War series, substituted other material — but the show just doesn't feel the same when the music is changed.

A set of the first season of "WKRP in Cincinnati," for example, disappointed a lot of fans by substituting music, as I mention below.

Question: Do the stars of the show "Two and a Half Men" sing the theme song? If not, who does?

Answer: The theme was performed by session musicians, with the cast members lip-synching.

Question: Why do "NCIS" and "Law & Order" in particular allow the background music to be so loud that you can't hear the actors and actresses? If no one else, I would think the actors and actresses would protest.

Answer: This is a regular complaint, and not only about the shows you mentioned. I've gotten letters about the sound on everything from "CSI" to "Days of Our Lives."

Here's the basic explanation: A lot of TV now employs more sophisticated audio than in the past, to sound better on home theater systems. But an older TV set, even one with stereo, may not be able to handle the elaborate mix, so some sounds get buried.

In addition, some shows mix the music high because the shows want the songs to be heard. Sometimes that's to make a dramatic point. Or the show has paid handsomely for the song, wants to showcase it and — in some cases — will include a plug for a CD containing it at program's end. And sometimes the mixing has to be done quickly to meet TV production deadlines, so it's not as good an audio mix as it should be.

Finally, there's a generational issue here. Younger viewers are more accustomed to loud music in shows, while older viewers find it distracting.

And the people making television, as a rule, care less about their older viewers than they do about the younger viewers.