Music history runs on imprecise calendar dates and well-defined sound worlds. The Baroque (roughly the late 1500s to 1750) was the era of tonality settling into the major and minor keys that still organize most Western music. Monteverdi, Bach, Handel, Vivaldi, Purcell. The harpsichord and the continuo group. Opera, invented in Florence in 1598, took off across the continent. The Classical period (about 1730 to 1820) brought the symphony, the string quartet, and the public concert. Haydn, Mozart, the young Beethoven. Patronage shifted from aristocrats to ticket-buying audiences. The Romantic century - from Beethoven's late works through the First World War - turned music into a national language, all Wagner forests and Chopin nocturnes and Verdi politics. Then the twentieth century broke the rules. Schoenberg replaced tonality with serialism. Debussy and Ravel imported gamelan textures from Java. Stravinsky put a riot in a Parisian theatre. Each period built on the last, and each city in Europe inherited at least one of them as a living habit.

If you want to hear Europe's best orchestras in their home rooms, the trip plans itself. Vienna's Musikverein is where the Vienna Philharmonic plays its New Year concert in the Golden Hall, broadcast to ninety countries. Berlin has the Philharmonie, Hans Scharoun's irregular pentagonal vineyard from 1963. Paris has the Philharmonie de Paris and the older Salle Pleyel. Munich has the Gasteig. Leipzig still uses the Gewandhaus, a hall whose acoustics Felix Mendelssohn himself helped tune. Amsterdam has the Concertgebouw, with the Royal Concertgebouw Orchestra playing under glass chandeliers and a vaulted ceiling that delivers two-plus seconds of reverberation - long enough to bloom, short enough to keep details intact. None of these halls require evening dress in the cheap seats. None require ticket prices that exclude students. The local audience treats them as civic infrastructure, the way other cities treat a beloved bridge.

Opera is theater set to music with the volume turned up. The major houses are spread across the continent. La Scala in Milan opens its season on December 7th, Saint Ambrose's feast day, with an evening so socially weighted that Italian newspapers cover it like a national event. Vienna's Staatsoper performs more than three hundred nights a year, an industrial-scale operation drawing the best singers in the world. The Royal Opera in Covent Garden, the Bayerische Staatsoper in Munich, the Opera Bastille and Palais Garnier in Paris, the Teatro Real in Madrid - each has its own repertoire bias and its own audience traditions. In Amsterdam, Dutch National Opera performs in Het Muziektheater, a 1986 building on the Amstel that locals call the Stopera because it also houses the city hall. Tickets are cheaper than in most other European capitals, the productions are routinely adventurous, and a glass of wine and a thirty-minute interval are included in the price.

The great fact about classical music in Europe is that you do not have to pay for most of it. Churches host concerts every weekend, sometimes free, sometimes with a small donation expected at the door. Cathedral organ recitals run all summer. The Concertgebouw itself stages free lunchtime concerts every Wednesday at twelve-thirty, mostly featuring student ensembles from the Conservatorium van Amsterdam next door. Village churches throughout France, Germany, and Italy program small festivals on summer weekends, often featuring local musicians playing pieces written for exactly that kind of room. Bandstands in city parks fill the warm evenings with municipal orchestras and brass bands. If you wander into any European city in July or August with no plan, you will almost certainly stumble across a free concert before sundown. The music goes on whether anyone has booked it or not.

Concert etiquette is less terrifying than its reputation suggests. Dress is whatever you would wear to a nice dinner; jeans are fine in any cheap seat in any hall. For purely instrumental concerts, applaud at the end of each piece, not between movements - though no one will throw you out if you misjudge it. At operas, applaud after any aria you enjoyed. Shout Bravo for a man, Brava for a woman, Bravi for an ensemble. Phones off, candy wrappers opened before the music starts, photography never. If you have a cough, bring lozenges. The point of all of this is not snobbery but the strange physics of a great hall - rooms like the Concertgebouw amplify a dropped program into a startling clatter, and the silence between notes is doing as much musical work as the notes themselves.