Un ballo in maschera, Opera Holland Park, London<br/>Proms 5 &amp; 6, Royal Albert Hall, London<br/>Orpheus and Euridice, Blackheath Halls, London

A scandal rocks Washington in Verdi's drama of politics and betrayal - but one bold addition in Martin Lloyd-Evans's production doesn't smack of the truth

How can something that feels so right be so wrong? From Tristan to Il tabarro, this is a question frequently explored in opera. Take Un ballo in maschera, set by Verdi in 18th-century Sweden, relocated to 17th-century Boston by Neapolitan censors, and staged in 21st-century Washington by Martin Lloyd-Evans. Here is a drama of politics, fidelity and betrayal in which loyal Renato's wife Amelia is so desperate to dispel the love she feels for Gustavo that she takes a drug prescribed by a fortune-teller. Now listen to the score and hear that intoxicating, irresistible shudder of strings and woodwind in "Oh, qual soave brivido": a sound hitherto unprecedented in this highly disciplined score. What can account for that? Smack, that's what.

Familiar images from film and television work in Lloyd-Evans's favour in Act I's immaculately choreographed traffic of White House catering staff, cleaners, speech-writers, flower-arrangers and security personnel, setting the scene for the masked ball of the title against designer Jamie Vartan's translucent Stars and Stripes. As Gustavo, the voiceless Rafael Rojas (David Rendall sang from the pit on the first night) has the heavy-set, easy charm of Bill Clinton, while Gail Pearson plays her skirt-suited Oscar as a perky aide. Renato (Olafur Sigurdarson) is a heavily-decorated General, Ulrica (Carole Wilson) a sequinned charlatan in a television studio. Where Lloyd-Evans comes undone is when he replaces The West Wing with The Wire. As a motif for the sudden deliquescence of Verdi's orchestration in Act II, having your heroine inject heroin is an interesting idea. Unfortunately, it undermines the logic of the following acts.

Since Amelia's humiliation is compounded by being filmed, stoned and swooning, on the conspirators' mobile phones, Renato's motives for joining their plot are muddled. Compared to a drugs scandal, an unrealised affair with the president is small beans.

Despite these inconsistencies, individual characterisations are persuasive. Broken and betrayed, a good man turned bad, Sigurdarson has a burning integrity that compensates for vocal roughness. As Amelia, Amanda Echalaz abandons herself to Verdi's soaring phrases of shame and desire but is most affecting while mutely recoiling at the kidnap of her son (Gianluca Volpe) by Horn (Simon Wilding) as Bugs Bunny silently capers on the screen in the background. In the pit, Peter Robinson keeps the City of London Sinfonia at a steady boil, with some lovely phrasing from the woodwind and an attractively oily cimbasso in the brass. There are some startlingly bold and imaginative theatrical details but realism is not something to toy with. As to the drugs, both Amelia and Lloyd-Evans should have said "No".

Little more than a week after the first blast of Stravinsky's Fireworks (Prom 1), the BBC Proms is part of everyday life. I've cooked to The Creation (Prom 2), ironed to Partenope (Prom 3), cleaned to the Eton Choirbook (PCM1) and cooked again while Listen(ing) Again to The Fairy Queen (Prom 7). Even accompanied by a hissing iron or a bubbling risotto, the sound is usually clearer than it is in situ, and there is something very special about this private yet communal listening experience. But I doubt a radio could have captured the acoustical effect of a packed audience barely daring to breathe during Bernard Haitink's performance of Mahler's Ninth Symphony with the London Symphony Orchestra (Prom 5). Now frail, Haitink seems more than ever to close in on himself when conducting late Mahler, barely moving his baton. Though the Ländler and Rondo-Burleske lacked bite, the architecture of the first and last movements was exquisite, understated, elegaic. The same night's pairing of the 1796 choral version of Haydn's Seven Last Words with James MacMillan's Seven Last Words (Prom 6) saw some beautifully measured musicianship from Manchester Camerata and the BBC Singers under Douglas Boyd, though the consonants were lost to an almost empty hall. Il terremoto excepted, the contrast between Haydn's unshowy solemnity and MacMillan's cinematic effects – variously luminous, pure and static, or unnervingly violent in rasping whispers and swarming strings – was fascinating. If Hollywood hasn't knocked on MacMillan's door, it should.

There's barely space to mention Blackheath Halls production of Gluck's Orpheus and Eurydice, but Elaine Tyler Hall's staging of this community project was so perceptive I have to squeeze it in. With Aaron Marsden and Marc Rosette's austere, evocative stage and lighting designs, a central performance of exceptional pathos from Wendy Dawn Thompson (Orpheus), a robust reading of the score from the amateur orchestra and chorus under Leigh O'Hara, and fabulous choregraphy from Stella Howard and the Laban Youth Dance Company, this was powerful stuff. You don't go to an amateur show for perfect tuning and perfect attack. But, Mariachi trumpets notwithstanding, Blackheath had the measure of Gluck's matchless concentrate of mourning and redemption.

'Un ballo in maschera' (0845 230 9769) to Aug 8