Countess Dora Pejacevic

WHEN an orchestra collectively puts down its instruments and sings the music it would otherwise be playing – well, it’s something you don’t witness every day. And the Budapest Festival Orchestra, who pull this singing stunt a lot, are no everyday ensemble. Under their free-thinking, maverick but genius founder/conductor Ivan Fischer, they rank high these days among the world’s great. And they sweep into the Proms this week for a three-concert residency on Aug 12-13 that no one interested in what a modern, forward-looking orchestra can do will want to miss.

Their first show, on Aug 12, is relatively standard repertoire, with Weber, Schumann, Mendelssohn – though don’t expect it to be standardly performed. Their third, the evening of Aug 13, features them on home ground in Bartok’s 3rd Piano Concerto (soloist Sir Andras Schiff). But earlier that day, at 2pm, they have a concert where no repertoire is advertised. And that’s because the audience will decide it – on the spot, selecting from a menu-list of 250 options.

How this will work remains to be seen (and heard), but it can only introduce a radical degree of spontaneity to the proceedings as they won’t have had much chance to practice in advance. And will they sing? You’ll have to go and find out. Details: bbc.co.uk/proms

• The Proms this week include another visitor from Budapest, albeit less alive: the Countess Dora Pejacevic, who was a Hungarian/Croatian Countess-turned-composer functioning around the time of the First World War. After her early death in 1923 (still in her 30s) her achievements largely disappeared from circulation. But she’s being reappraised now, with a vengeance, and extraordinary things have come to light – not least a symphony that gets performed by the BBCSO under Sakari Oramo at the Albert Hall on Aug 14.

But perhaps the most extraordinary item in a Proms week with a pointedly Hungarian theme is Gyorgy Kurtag’s Endgame: an operatic adaptation of Samuel Becket’s absurdist play about two people with no legs who live in dustbins. Premiered at La Scala Milan five years ago, this is its first performance in the UK – semi-staged on Aug 17 with the BBC Scottish SO under Ryan Wigglesworth. And in the cast is contralto Hilary Summers who sang one of the dustbin-dwellers in Milan – which no doubt gives this Albert Hall show useful validation. All Proms details bbc.co.uk/proms. And remember, everything gets broadcast live on Radio 3.

• Almost the only competition to the Proms this week comes from the little Grimeborn Festival at the Arcola Theatre, Dalston – which is offering the British premiere of a long-forgotten opera by baroque composer Domenico Zipoli. A Jesuit missionary to Argentina in the early 18th century, his music fuses South American and European sound-worlds, with whole chunks of vocal writing that responds to Inca singing. And this opera, called Loyola, celebrates Ignatius, the formidable and powerful founding father of the Jesuits. A spiritual curiosity, it plays Aug 11-12. See arcolatheatre.com