Even seemingly immortal singers grow old. Sir Bryn is closer to the "Martinmas summer" of Shakespeare's and Verdi's Sir John than when first he put on the fat suit at the Royal Opera 18 years ago. Even if he walks the gouty walk that matches the belly, vocally he seems richer than ever.

The Royal Opera’s Boris Godunov production made the short trip from Covent Garden to South Ken for the company’s appearance at the 2016 Proms. The opera (here in its original 1869 version) is a good choice for concert presentation: as Antonio Pappano writes in the programme, much of its music approaches oratorio. That is particularly true of the choral numbers, and the work is a tour de force for the Royal Opera Chorus. But every aspect of the music is this production is strong, so the gains balanced the losses, despite the minimal visual presentation.

Russian bells and spinning tops dominate Richard Jones's predictably unpredictable take on Musorgsky's saga of a conscience-stricken Tsar. Latter-day purism tends to insist on the composer's seven-scene 1869 original – possibly for economic more than artistic reasons – and this two-hour-plus, interval-free whizz through seven years of Russian history is the most faithful to the first score I've heard.

There’s a good deal to be said for semi-staged opera. It concentrates the mind in a particular way; it brings the orchestra more fully into the action; it moves the singers closer to the audience; and above all it reduces – even removes – the power of the director to superimpose some crackpot notion of his or her own on the dramaturgic design of the composer and librettist.

Stop miking Bryn Terfel. Stop over-miking musicals; the show voices in a hybrid cast don’t need much. Too much ruined English National Opera’s recent Sweeney Todd, and in this Proms adaptation of Grange Park Opera’s summer crowd-pleaser it sent the voices ricocheting around the Albert Hall, making mush of the words and stridency of the few belt-it-out moments.

Many matches are made in Fiddler on the Roof but the matchmaking prize goes to Grange Park Opera for getting Bryn Terfel to take on the role of Tevye. Having only recently played Sweeney Todd, and indeed throughout a varied career, Terfel has proved that he can treat lighter music with respect and sincerity, not to mention plenty of good humour.

There’s a lot to be said for concert performances of Wagner. Not only are you spared the post-prandial lucubrations of aspirant directors – the moonmen and the fighter pilots, the jackboots and the biogas installations. But it’s possible to concentrate on Wagner’s greatest theatrical gift: not his stagecraft or stage imagery, but his management of time and psychological growth through purely musical means.

Still they keep coming, 35 years on from the London premiere of Sondheim's "musical thriller": Sweeneys above pubs, in pie shops, concert halls and theatres of all sizes, on the big screen, Sweeneys with symphony orchestras, two pianos or a handful of instruments wielded by the singers, Sweeneys as musicals and as operas, the dumpy and the tall. Which type was this one? Not a vintage English National Opera production, that much seems clear.

Like the Dutchman himself, Tim Albery’s Der fliegende Holländer makes its inevitable return to the Royal Opera House. Unlike the Dutchman, however, this production has broken free of its cycle of repetition. Perhaps expectations have changed, perhaps after two outings I’ve just surrendered to Tim Albery’s severe and sober staging, but for the first time since its 2009 debut this ghostly ship finally comes in to emotional harbour.

“Watch out for the dog!” instructs Covent Garden’s programme for its latest revival of L’elisir d’amore. These creatures do have a way of stealing shows, but the canine who dashed across the flat Italian cornfield after Dr Dulcamara’s decrepit lorry had some impressive competition – from Vittorio Grigolo’s behind.