Steve Reich [Bernard Gotfryd]

WHAT’S the greatest orchestra on earth? is one of those questions persistently thrown at music critics. And there’s no convincing answer, because no one these days travels enough to hear the contenders on a regular basis.

But in terms of reputation, a fair response would be the Berlin Philharmonic. It’s the musical equivalent of a Rolls Royce: sumptuous, sleek, rich in old-established glamour. And its sound is unmistakeably expensive – as you’ll hear when it plays the Proms this week in two concerts lined up to be highlights of the season.

Sep 3 brings home-ground Beethoven. But on Sep 2 it’s the less obvious territory of Elgar: his Enigma Variations. And it will be interesting to see (a) what conductor Kirill Petrenko makes of so magnificently English a score, and (b) whether he reveals any sense of what the Enigma might be. Famously, this piece is a set of variations on a theme you never actually hear. Implied rather than stated, Elgar said the hidden theme was “so well known it’s extraordinary no one has spotted it”. But to this day it’s a mystery. Guesses range from Auld lang syne to Rule Britannia, with no obvious solution. And maybe Elgar didn’t really intend one. A keen amateur cryptographer, he may have been playing games with us all. Who knows?

Either way, it’s deathless music and comes paired in this concert with a deathless symphony, Tchaikovsky’s 4th, which has secrets of its own that commentators argue about. Petrenko, who is Russian by birth, may have things to say there as well.

• Also flying into the Proms this week is the Oslo Philharmonic: not so grand as Berlin but still distinguished, and conducted on Aug 29 by the dynamic Mirga Grazinyte-Tyla who made her name in recent years running the CBSO.

With a programme that includes Stravinsky’s Violin Concerto in the hands of another electrifying female musician, Patricia Kopatchinskaja, expect a sonic fireworks night.

• There’s been a lorry-load of large-scale Berlioz in the Proms this year, with his popular Symphonie Fantastique, his monumental Requiem, and now – on Aug 30 – his so-called “legende dramatique”, The Damnation of Faust. Half-way between opera and oratorio, it probably fits the concert hall better than the stage: you close your eyes, follow the music, and imagine what’s going on. Done here with Gerald Finley as the diabolical Mephistopheles.

• Among this year’s music anniversaries is the 90th birthday of American minimalist Steve Reich whose Hebrew psalm settings, Tehillim, feature in a late-night Prom, Sep 2. Courtesy of the Gesualdo Six and assorted percussionists. All Proms happen at the Albert Hall, and are broadcast live on Radio 3: bbc.co.uk/proms

• There’s not much happening outside the Proms just now, but the Arcola Theatre’s Grimeborn opera festival has Handel’s Giulio Cesare, Sep 2-5. arcolatheatre.com

And finally, a country house opera festival you can access by underground. Vache Baroque is a newish venture in the grounds of a 17th-century mansion near Chalfont St Giles at the end of the Metropolitan line. And Aug 29-Sep 6 it’s running Shakespeare’s Tempest reimagined as a semi-opera, with music by Purcell, Locke and others. Could be interesting. But take an umbrella. Should it rain, there’s not much cover and it’s chaos. vachebaroque.com