The Church, in an enlightened moment, forbade composers like Bach to stage any false drama to distract from proceedings. This meant the music had to stand or fall on its own merits. Imagine a single white spotlight, bare stage but for two guitars, bass, amps and drum kit.
Songs are short. A tune about the meaninglessness of life and the utter certainty of death (much like the lyrical content of metal, then) can be done and dusted in one minute of stone-cold brilliance.
There's little padding between classic songs like there is in opera.
It's Sunday morning, there's no booze and only the genius of Bach and his musicians will keep them coming back for more next Sunday. Good choral music has no filler.
If Auckland's St Matthews-in-the-City sold beer and wine with their Sunday passion-fest, then I, for one, would be a regular church-goer.
Particularly if they staged Bach's St Matthew Passion the way Paul McCreesh, founder and director of the Gabrieli Players, does it.
McCreesh chose a 12th century gothic church in Denmark because of the acoustics and its two enormous kick-arse modern organs. Against these keyboard behemoths, he arranged four violins, a viola, two cellos and a double bass and a couple of flutes, recorders and oboes. In rock terms, that's one guitar, bass and drums.
Most controversially, there are only eight singers for the lead roles and chorus. That's 100 singers short of the usual muster. This is back-to-basics stuff, as primal as Elvis in his 1955 Sun sessions in Memphis. It certainly sounds as otherworldly as Elvis.
Listen to Erbame dich or Aus Liebe (both featuring the incomparable Czech mezzo soprano Magdalena Kozena) and you're not a million miles away from Presley's evocation of 1950s guilt, sex and redemption in Mystery Train and Blue Moon.
The St Matthew Passion is as long as most opera - two hours and 40 minutes. Yet Bach manages to pack in nearly seventy songs, each, on average, clocking in at under two minutes 30 seconds.
There's no mucking about - you get an astonishing melody from the most plagiarised composer in history, lyrics (mostly about fear, death and redemption), a bit of instrumental flash and then - Bach has left the building.
It is an unparalleled sustained piece of songcraft and in that sense it's more like a Motown revue, in that the hits keep on coming.
There are some duffs among the 68 songs. Watch out for what's called "recitatives" (roughly, musical interludes) as this sometimes involves people shouting at you in German. Mostly those bits are good though.
McCreesh's Passion, recorded in 2003, is the high-water mark of the modern re-interpretation of choral music, the first to apply the less-is-more approach to this piece.
Other versions are pale, wan creatures compared to this masterpiece. This highlights the other peril for general music fans approaching classical music: there are hundreds of versions of Bach's St Matthew Passion, most of them dodgy.
I once bought what looked a terrific compilation of 1950s rock 'n' roll only to discover it was a German tribute band masquerading as Buddy Holly, Carl Perkins and the like. The horror.
Buying classical music can be a lot like that. Many versions of classical classics are like listening to Jailhouse Rock sung with a German accent. You have to get the right version. This is it.
Lowdown
CD: Paul McCreesh's St Matthew Passion by Bach
Key track: Erbame dich, mein Gott
Pop equivalent: The complete Sun Sessions, Elvis
Download: Erbame dich, track four, disc two at here.
- TimeOut