The best shows send you out of the theater humming the songs. "Show Tunes" sets you humming the songs as you turn the pages.

It also sets your eyes popping, at least occasionally, at things you didn't know.

Writing of "Show Boat," Steven Suskin tells us: "With 'Ol' Man River,' Hammerstein wasn't trying to make a far-reaching social statement: His primary concern was to bring the action downstage while the massive 'Cotton Blossom' set was being struck."

And we learn that the great David Merrick Quote-Ad Hoax had been planned for some years. It had to await the retirement of Brooks Atkinson, for that New York Times critic was the only Brooks Atkinson in town.

It also had to await a lavish Merrick production that was heavily panned by the press. That came in 1961 with "Subways Are for Sleeping." After the opening, Merrick ran a full-page ad quoting New York citizens who had the same names as the city's critics. The citizens, seen in head shots, loved the show.

The reason Suskin knows things like that is that, in spite of the book's very substantial scholarly achievement, he is not a scholar. He is a Broadway denizen himself.

Suskin is a company manager who started with Merrick as a gofer and has been associated with dozens of Broadway shows, including "Shenandoah," "The Best Little Whorehouse in Texas" and "Amadeus." Until its recent closing, he was working "Singin' in the Rain." A pro.

This adds two important things to the book.

Suskin knows how real theater really works. In his pithy comments on the shows740294657he combines inside information from his research and from simply being on Broadway, with that street's traditional warm heart and cold eye.

Speaking of that cold eye: "Curiously enough, considering the diversity in subject matter, 'La Cage Aux Folles' and 'Annie' were pretty much equally matched in quality of score, book and direction, which is to say monotonously mediocre."

And of Doug Henning's "The Magic Show," he comments that "the great magic feat here was pulling a long-run hit out of a very empty hat."

Right up front, we find that although by most accounts, including this one, the American musical began with "Show Boat" in 1927, by that time, composer Jerome Kern had been working on Broadway for 24 years, of which very few produced any titles we have heard of. Further, those few titles are known mostly from recent revivals: "Very Good Eddie," "Leave It to Jane."

The familiar songs from that quarter-century of steady work include only "They Didn't Believe Me" and "Look for the Silver Lining," and perhaps one or two others.

Suskin is marvelous at tracing recycled songs from flop to hit, even through changes of title or lyric. Lyricist P.G. Wodehouse's "Bill," which had been used in two earlier shows, was included in the Kern-Hammerstein "Show Boat." And the song "Leave It to Jane" first appeared as "Whistlin' Dan" in a different show.

"Show Tunes" belongs in any library of the theater, and it will prove invaluable during late-night singing discussions.

The heart of the book is the on-stage careers of 30 mainline Broadway composers from Kern to Stephen Schwartz. The last section notes and annotates significant Broadway scores by others: Eubie Blake's "Shuffle Along" and Harry Tierney's "Irene" to Henry Krieger's "Dreamgirls" and Roger Miller's current "Big River."

You also get the productions in chronological order, major collaborators and a bibliography with a note on finding sheet music in libraries and for sale. The book is indexed for song titles, show titles and show people.

In short, "Show Tunes" takes an inclusive view of its subject, is based on intensive research and is efficiently organized.

As an 11 o'clock number, try Suskin's incisive judgment of where we are now: "Michael Bennett and Bob Fosse have perfected the concept musical, built on plenty of concept and (often) very little else. Talent frees them from relying on book, music, lyrics; instead of assembling a production around material, they seem to start with movement and add on songs, plot, etc., etc. Jerome Robbins worked in the same way, but he insisted on first-rate material -- which explains his absence since "Fiddler on the Roof."

The classic Broadway hyperbolic compliment says an actor could read the Manhattan telephone directory and make an audience laugh and cry.

Like the phone book, "Show Tunes" is a book of lists.

But even without Rex Harrison or the Cronyns to perform it, it makes you sing and dance all over your memory.