Mark Prendergast, the final page of The Ambient Century: From Mahler to Trance: The Evolution of Sound in the Electronic Age (Bloomsbury) informs us, “is the author of more than one million words on New & Electronic music.” You might think that, in the process, he’d have learned how to put them together. You’d be wrong. His three-sentence-long biographical note includes a dangling participle and lacks two desperately needed commas; the book itself runs nearly 500 ghastly pages. At the very least, his editor deserves a forced re-education.

Almost every page has some kind of factual boner (the file format MP3 is described as a “tiny box”) or piece of plain awful writing (Carlos Santana’s “openly trilly style and use of lengthy feedback sustains was a compliment to Jimi Hendrix. His composition style a virtue of Miles Davis’s modality. His instrumentality a product of blues intersecting with Latin-American virtuosity.”). Prendergast doesn’t seem to notice when his mistakes are contradicted: six pages after he credits La Monte Young with the “radical invention of ‘just intonation,’ ” he quotes Terry Riley explaining that just intonation occurs naturally in Indian, African, and Middle Eastern folk music. He almost never identifies the source of the critical judgments he’s continually citing; instead, he attributes them to “many” (Todd Rundgren was “seen by many as the Prince of the ’70s”) or presents them in the passive voice (on Karlheinz Stockhausen’s Mantra: “The result was considered to be beautiful and quasi-meditative”). And his habit of capitalizing every genre name except rock and blues — not just “Ambient” but “Space-Hop,” “Ravedelia” and “Hard Bop” — becomes unbelievably annoying.

Following a page and a quarter of throat clearing by Brian Eno, The Ambient Century opens with 90 pages about “the electronic landscape,” an omnium gatherum of blather about composers, performers, and instrument inventors — Gustav Mahler, Erik Satie, Miles Davis, Toru Takemitsu. Prendergast has to strain to include a lot of them: we’re told, for instance, that “the high points of twentieth-century electronic music, like Pink Floyd’s Dark Side of the Moon, were first envisaged in Debussy’s ample imagination.” In the words of Wolfgang Pauli, that’s not even wrong.

Reheated biographical details and absurd puffery appear in place of useful information. We learn of Iannis Xenakis that “the rise of Nazism brought out a rebellious spirit in him, as in many others.” A chapter on Erik Satie prattles on about his early piano lessons, his time in the army, and his 12 identical velvet suits and notes that his work “literally blew away the pomp and rhetoric of the old order.” (No, it didn’t — not literally, anyway.) Prendergast also spends all of half a sentence on Satie’s idea of “furniture music,” the pillar on which ambient music is built, and gets it wrong. Satie described “furniture music” as “music that would be a part of the surrounding noises and that would take them into account. . . . I see it as melodious, as masking the clatter of knives and forks without drowning it completely, without imposing itself.” Prendergast calls it “background Ambience for boring intervals in concert music.” Bzzzt.

The rest of the book is divvied up into sections on “Minimalism, Eno and the New Simplicity” (the compositional tradition of the last few decades, plus the ECM record label and Brian Eno), “Ambience in the Rock Era” (everyone who’s ever made an interesting-sounding rock record, from Jimi Hendrix to Led Zeppelin to U2), and “House, Techno and Twenty-First Century Ambience” (you know, dancy stuff). Prendergast tries to be comprehensive but ends up uncomprehending; the result is a volume on ambient music that includes chapters on Country Joe and the Fish and Simon & Garfunkel but omits, for instance, Alvin Lucier and his remarkable piece “I Am Sitting in a Room.”

The genuine disaster of The Ambient Century is that Prendergast begins it by launching straight into his half-digested catalogue — that is, without establishing what exactly it’s about, or what he means by “Ambient.” The word becomes a catch-all for every piece of music he’s ever liked or been told is important. (He praises “Michael Stuart’s Ambient drumming” on Love’s Forever Changes. What?) In its strictly limited sense of being, in Eno’s words, “as ignorable as it is interesting” — of coloring its environment without demanding attention — ambient music is a fascinating idea, but Prendergast doesn’t seem to have much interest in it. In fact, The Ambient Century is haunted by the specter of the book it might have been: the author occasionally hints that sound recording transformed music from an activity based in performance and observation to a commodity that could be experienced in any context. There could have been a thesis there, and a clear narrative, and a way of casting the last hundred years of music in a new light. Instead, all we get is a vague, pompous wave at Prendergast’s CD collection. After all, any music is ambient if you turn the volume down low enough.