Weighing up the opposition seems the only adequate expression for matching this 10-kilogram giant against its more obvious rivals.

While the Penguin Opera Guide covers 450 works in 500 pages, and the New Kobbe deals with 500 works in 1,000 pages, the New Grove clocks up an astonishing 1,800 operas, 3,000 composers and 2,500 singers and performers in its 5, 300 pages.

That’s in addition to lengthy articles on hundreds of subjects such as voice types, the socio-logical and philosophical nature of the genre, allegory, libretti, casting, rehearsals and films. There are even four pages on other operatic dictionaries.

But it’s no dinosaur. Between Aachen (scene of an early production of Die Zauberflote) and Zylis-Gara (a Polish soprano) there are countless fascinating observations. Its scope is generous, with not only 10 pages on Berlin but lots on Irving of that name, as well as coverage of Kern, Loesser, Cole Porter, Sondheim, and (yes) Lloyd Webber. It misses some recent works such as Thomas Ades’ Powder her Face, Harrison Birtwistle’s The Second Mrs Kong, Param Vir’s Broken Strings and Judith Weir’s Blond Eckbert, though Tippett’s New Year is there in all its experimental strangeness.

The true stars are the big pieces - scholarly articles (with musical examples) by such experts as Roger Parker on Verdi, Barry Millington on Wagner, Julian Rushton on Mozart, David Murray on Richard Strauss, and Richard Taruskin on Mussorgsky and Stravinsky.

Arnold Whittall’s essay on The Turn of The Screw succinctly covers Britten’s debt to Henry James as well as anal-ysing how the horror gets into the harmony.

This is not a book to pop into the car when you’re off to see Rigoletto and can’t quite remember who kills whom. Even a lover of The Cunning Little Vixen might quail at reading a bibliographical list of 42 articles in Czech on Jan ycek.

You could listen to The Ring at least fourteen-and-a-half times while reading this extraordinary book. But it’s an awesome and compelling addition to a library.