Aristotle wrote that classical tragedy should evoke pity and awe. With Richard Strauss’s Elektra, the awe can be taken as read: a certain irreducible level of epicness is written into the score, even if – like Sir Antonio Pappano on the first night of this new production at the Royal Opera – a conductor takes the composer’s advice and treats it like Mendelssohn’s ‘fairy music’. But I genuinely hadn’t expected quite so much of the other emotion – pity, or if you prefer, compassion. There it was, though, welling up from the bottom of the orchestra, worrying away at one’s preconceptions, until in the Recognition Scene the eyes started to prick and the heart started to race in that way that isn’t exclusive to opera, exactly, but does seem to happen more often in the opera house than with any other art form.

Time and again, the shields drop and the characters’ damaged souls reach out and clutch at you

I’m struggling to attribute that cumulative impact to any one element of Christof Loy’s staging, because pretty much everything hits the spot. As Hofmannsthal’s libretto specifies, the set (by Johannes Leiacker) represents the prison-like back courtyard of a palace complex, here located in a generic mid-20th century. Doors swing open and lights flick on indoors, where the household can be glimpsed rushing about in panic as terrible events unfold, unseen. Loy’s storytelling is lucid, but shot through with visual poetry. The costumes spell out the social hierarchies (a maid’s outfit for the degraded Elektra; full ball gown and jewels for her murderous mother), and a servant brings a flaming torch to throw ritual light on the final bloodbath.

It’s deceptively simple and reassuringly naturalistic. Loy is always an interesting director but I’ve rarely seen his vision focused as effectively as it is in Elektra. The cast was as good as you’d expect it to be: Nina Stemme (Elektra) still has that remarkable ability to clothe penetrating force in luminous warmth; and Karita Mattila (Klytämnestra) veers from searchlight brilliance to gurgling, horror-struck low notes with all her accustomed bravura. Sara Jakubiak sings brightly as Chrysothemis, the only character who is even close to sanity (her pretty party dress suggests her desperate longing for normality). In his role as Orest, Lukasz Golinski’s heroic, tightly honed baritone is perfectly suited to his plot function as the implacable instrument of divine justice.

But this is opera. The singing, however fine, will never be enough, and Loy and his cast give us more – much more. Take the way Jakubiak lets that shining voice tighten and quiver as emotion overcomes her; or Mattila’s weird snarling smile as she retreats from Elektra’s presence: a woman both deserving of, and infinitely beyond, pity. Time and again, the shields drop and the characters’ damaged souls reach out and clutch at you. Elektra is often played as a half-crazed spitfire, but not here. Small, defiant and intensely vulnerable in her maid’s outfit, she lies huddled on the floor as she pours out her fury and pain – which, clothed in Stemme’s heart-subduing tone, comes across more as longing than as hatred.

That bruised and frightened humanity is the heart of this production, and it’s testimony to Loy’s gifts that it extends all the way to Pappano’s conducting, which – light-footed and silvery in Strauss’s flashier passages – trades brute force for redemptive lyricism. It’s a genuine trade-off. If you’d hoped for the full sonic violence this opera can offer, you might feel frustrated, though I suspect you’ll still be struck by (for example) the lethal stillness that Pappano finds in the deep brass chords that proceed Orest’s final act of vengeance.

Even Rattle-sceptics would be pushed to deny he gets better and better in Janacek

This new Elektra doesn’t offer anything as clean or as reassuring as pure catharsis. There’s a different agenda at play and – believe it or not – it’s about love. Who knew that Strauss and Hofmannsthal still had the power to surprise – or that this opera, one of the 20th century’s great proto-modernist monsters, could yield up such tender, troubling new truths? This will be Pappano’s last wholly new production as music director at Covent Garden, and if in many ways he’s playing against type, there can be no question that he’s putting the drama, and his company’s collective achievement, first. That deserves respect.

A concert performance of Janacek’s Jenufa with the London Symphony Orchestra, meanwhile, found Sir Simon Rattle playing very much to type. Janacek has been a Rattle speciality since the early 1980s – and even the dreariest of Simon-sceptics would be pushed to deny that he gets better and better in this rep.

Violins lapped with baby-breath softness as Agneta Eichenholz (a plaintive, touching Jenufa) pleaded with Katarina Karneus’ Kostelnicka; the violas and horns unfurled gently rocking melodies, accumulating tension like static electricity before tumbling forward into the next phrase. The LSO was on needle-point, and the whole thing had a tautness that was tangible even in moments of repose. It’s the opposite of Elektra: with Jenufa, the pathos is baked in. It was the inevitability – the awful, accelerating tragic momentum – that surprised the audience in this performance.

Eichenholz and Karneus headed an impressive cast, and if Karneus, more than ever, made Kostelnicka feel like the true heroine of this opera, the same commitment extended all down the line, with Ales Briscein’s Laca matching Eichenholz for honest, understated ardour. Nicky Spence was a relatably blokeish Steva, throwing himself energetically at a thankless role.

Wouldn’t it be great to see this team in the theatre? Previous LSO/Rattle opera projects have introduced an element of semi-staging but with Jenufa requiring a full chorus the platform was rammed, leaving no room for the soloists to do much more than line up behind music stands. Had the opera been in Birmingham, Glasgow or Manchester this would not have been necessary. But tell me again how the Barbican is perfectly adequate; and how London doesn’t really need a proper modern concert hall.