In the late 1990s, I attended a seminar at which broadcast legend Norman Corwin — a man who almost single-handedly defined radio’s Golden Age — took questions. The crowd of working broadcasters and radio historians asked him about everything from old-time technology to the process he used to select his topics.

I bring this up for two reasons.

First, Corwin is mentioned in David and Susan Siegel’s book “Radio and the Jews” as one of the few mainstream broadcasters who devoted airtime to positively portraying Jews during the first half of the 20th century.

Second, despite his pedigree, no one at the seminar asked Corwin anything that even vaguely related to Jews. As far as today’s radio geeks were concerned, “radio” and “the Jews” were two separate topics.

The Siegels’ book is a welcome correction to that attitude, reminding us that radio from the 1920s through the 1950s was the same kind of lightning rod that Hollywood is today.

The two radio broadcasting titans — NBC and CBS — were both run by Jews, and Jews made up a substantial number of the executives, on-air talent and behind-the-scenes crews who made radio work.

Yet when the finished product was beamed into homes across the nation, Jews were virtually invisible. Anti-Semites said the Jews’ involvement with radio amounted to a conspiracy to control the media.

Sound familiar? Whatever the Yiddish word is for “déjà vu,” “Radio and the Jews” evokes it.

“Radio and the Jews” also traces, albeit unwittingly, the source of a very contemporary scourge: celebrity causes. Many of the first big-name celebrities who tried to motivate the American people to care about world affairs were radio personalities who demanded the public wake up to the evils of Nazism. Jews, such as Eddie Cantor, and friends of Jews, such as Alexander Woollcott, suffered career setbacks because they would not let their broadcasts turn a blind eye to Hitler.

Now, how is it when they did that they were noble, but George Clooney (speaking about the crisis in Darfur) is just annoying?

“Radio and the Jews” offers no theory to account for this. In fact, it has no theory to account for anything. It is a textbook-like collection of facts that begs for, but does not provide, insight. Instead of attempting to provide a cohesive narrative, or at least group similar issues together, it runs through a collection of chapter subjects in a way that demands to know whether this will be on the test.

The book is impressive for its comprehensive approach and its total lack of imagination. It manages to be fascinating without ever being interesting. This could have been a book that appeals to anyone interested in history; instead, it’s a book that will appeal only to those interested in Jews or radio.

It does, however, come with a CD — 17 tracks of obscure, hard-to-find Jewish material from radio’s classic years. These clips aren’t invaluable — like all good antiques, they come with the sense that somehow you’ve seen them all before — but they do illustrate just how far we’ve come, despite the déjà vu.

“Radio and the Jews” isn’t very good reading, but I’m mighty glad to have read it.

“Radio and the Jews,” by David S. Siegel and Susan Siegel (283 pages, Book Hunter Press, $24.95)