TO MARK ARMISTICE DAY in 1943, the New York Philharmonic played the first nine bars of Beethoven’s Fifth Symphony, paused for a minute of silence, and launched into “The Star Spangled Banner.” Earlier that year, a recording of the same symphony had accompanied the official German radio broadcast announcing the Nazi army’s defeat at Stalingrad. The Fifth was played as the finale to concerts at Victorian London’s Crystal Palace during the Great Exhibition in 1851; along with “La Marseillaise” at an 1848 Paris Conservatoire concert to benefit wounded revolutionaries; and over and over, as though on a loop, on Radio Free Prague during the 1968 anti-Soviet rebellion in Czechoslovakia. A performance of the Fifth inaugurated the Chicago Orchestra Hall in 1904, and it was the first symphony to be put on a record, by Friedrich Kark and the Odeon Orchester in 1910. Its opening theme has accompanied cartoon characters from Daffy Duck to Marge Simpson and been used to advertise cars, shoes, Californian white wine, and Japanese frozen noodles.

Once a piece of music has been pressed into service for such diverse political, ideological, and commercial aims, can we still hear it? That’s the question posed by The First Four Notes, Boston Globe music critic Matthew Guerrieri’s history of the symphony’s famous opening theme — and, more importantly, what people have heard in it over the more than 200 years since its premiere. In a way, Guerrieri isn’t the first to ask the question. Early on, he describes a Dadaist experiment in which the avant-garde composer Stefan Wolpe set eight phonographs to play a recording of Beethoven’s Fifth simultaneously but at different speeds, in what Guerrieri suggests was a futile attempt “to recreate the disorientation that it could cause when it was newly born.” That was in 1920, and the piece had already become a concert hall staple; today, its first four notes are so ubiquitous that most of us can’t recall where or when we first heard them. Once disorienting, even revolutionary, that opening motif now serves as common cultural shorthand for a tangle of abstract associations — fate, victory, death, greatness — and Guerrieri’s ambitious project is to identify the origins of each strand.

This approach makes The First Four Notes as much a history of ideas as of music, with substantial discussions of thinkers from Marx and Engels to Thoreau and Schopenhauer who have applied their theories to Beethoven’s life and work. But Guerrieri is often at his best when he leaves aside what the notes might mean in favor of the music itself. His straightforward reading of the Fifth’s opening phrase highlights its harmonic and rhythmic ambiguities: The first eight pitches (G-G-G-Eb, F-F-F-D) could plausibly belong to either the symphony’s key of C minor or its Eb major relative; the eighth-note rest followed by three eighth-notes sounds to some ears like a triplet; fermatas over the long, phrase-ending notes (Eb and D) obscure the meter. While it might be impossible for present-day listeners to fully enter the mindset that made all this so shocking at the Fifth’s 1808 premiere, Guerrieri’s spare exegesis strips away some of the rhetoric around the piece, by providing a concrete inventory of the musical elements that have often inspired overwrought and imprecise description.

While it’s tempting (and typical) to explain the...