Prom 7, Royal Albert Hall, London<br/>Prom 4, Royal Albert Hall, London<br/>The Elixir of Love, Blackheath Halls, London

From Mahler's "Jauchzet auf!" to Wagner's "Wach' auf!" and Verdi's "Plebe! Patrizi! Popolo!", you couldn't move for exclamation marks in the first few days of the Proms.

By Wednesday night, season ticket holders had scaled the Alps, quelled a Genovese rebellion, resisted a Spanish invasion, and witnessed the humiliation of a lovestruck Bavarian critic. Yet it was the quietest notes of the week that most beguiled.

Chopin's Nocturnes do not require exclamation marks. Played by Maria Joao Pires, in Prom 7, they seemed not to need any audience, let alone one of several thousand. These somnambulist arias for solo piano melt into ellipses, their dynamics shaded from the faintest pianississimo to a cool mezzo forte, their mood abstracted. Pires has little interest in performance – a polite bow indicates she is aware of her public. The dialogue is between her and the music.

Delicate but never fey, Pires's E flat major Nocturne (Opus 9, No 2) is a gentle waltz between ex-lovers, its shivering trills explicitly sexual, the F major (Opus 15, No 1) a wistful orchestral sketch. The second Nocturne from the same set has a troubled, furtive quality, while the third vacillates between girlish fantasy and subdued melancholy. In Opus 27, her C sharp minor Nocturne acquired Beethovenian tartness, the D flat major, honeyed warmth. Opus 62 and 72 demand a more extrovert approach, yet here too the bel canto ornamentation was understated, while the Lento con gran espressione became a miniature Requiem. Elegantly shaped and articulated, with the most distinctive response to the colours of individual keys, this was a revelatory, intimate reading.

If Pires wins the prize for the softest notes to be played in the first week of the Proms, Simon Trpceski comes a close second. Monday's performance of Rachmaninov's Second Piano Concerto with Vasily Petrenko and the Royal Liverpool Philharmonic Orchestra (Prom 4) was crisp and confident from the agonised gasp of the opening chords to the pellucid arpeggios of the Adagio and the taut, athletic finale. Petrenko is more partner than accompanist in this work, carefully establishing and maintaining dramatic tension through the aching melodies and deft counterpoint. I remain unpersuaded by Mahler's orchestration of Schumann's Manfred overture, but Tchaikovsky's symphony on the same subject was thrillingly realised – all silk and angst and tambourine-shaking demons.

Staged in the round and performed in Amanda Holden's translation, Harry Fehr's pretty, witty production of The Elixir of Love for Blackheath Halls Community Opera propelled Donizetti's romcom into rural 1940s Britain, with a 100-strong chorus of land girls, fire wardens, home guards and schoolchildren, and some bunting, sandwiches and scones for the wedding party. In a neat twist to the first scene, Nicholas Sharratt's Nemorino is a bookish romantic whose copy of Tristan and Isolde is snatched and roundly mocked by Elena Xanthoudakis's Adina – giving her something concrete to regret and him some much-needed intellectual clout.

You can fill a hall with friends and relatives, but holding their attention – from the texting teens to the cognoscenti – takes skill. Fehr's movement direction was excellent, making full and lively use of the hall while not losing focus on the lovers. Robert Poulton's whisky-swigging spiv of a Dulcamara arrived on a bicycle, while US Army Sergeant Belcore (Grant Doyle) had pockets full of sweets to keep the children quiet. Every member of the chorus seemed to know exactly who they were supposed to be, and each one developed with the story.

Despite some unforgiving speeds from conductor Nicholas Jenkins, the orchestra played with style and spirit, with particularly fine work from the flute and harp. The women's semi-chorus, led by Helen Bailey's Giannetta, was excellent. Having promised a furtive tear last week, I managed rather more than one. Xanthou-dakis's transformation from brittle tease to heartbroken penitent was deeply affecting, and Sharrat's Act II aria simply lovely. Elixir was Blackheath's fifth production. At this rate, their sixth will be a must-see.

Next Week:

Anna Picard returns to Holland Park for Verdi's La forza del destino