Even in a big orchestral concert, you’re bound to note Berlin Philharmonic principals as among the best instrumentalists in the world. I cited five in the central instalment of Simon Rattle’s Sibelius cycle on Wednesday. Of those, only viola-player Amihai Grosz figured in the Octet, joined by seven more players of peerless sophistication. Rattle may have been taking the evening off – unless he was brainstorming plans for a new concert hall elsewhere in London – and the keynote here was freed-up enjoyment.

A memorial concert to a busy man. Alexander Ivashkin, who died last January, was a cellist, a scholar, a teacher, an authority on Russian music, and much else besides. This evening’s concert faced up to the daunting challenge of commemorating the many diverse aspects of Ivashkin’s career. The results were predictably wide-ranging, yet always coherent, and an impressive focus was brought to this mixed but never eclectic programme.

While the Berlin Philharmonic's progress through London with Simon Rattle has grabbed the column inches away from the rest of the capital's classical music offerings this week, a delightful mostly Ravel programme from the Philharmonia should not be passed over.

Andris Nelsons is flavour of the month in London. He is in town to conduct The Flying Dutchman at Covent Garden, but between performances he is moonlighting at the Festival Hall, giving two concerts with the Philharmonia. This, the first, opened with a serviceable Mozart Piano Concerto No. 25 from Paul Lewis, and concluded with a Bruckner Third Symphony that was in a different league entirely.

The concert season’s title may be Rachmaninoff Inside Out. But the work that dominated and got people talking in yesterday’s instalment of Vladimir Jurowski’s London Philharmonic series was by another composer entirely. “Weird, isn’t it?” said the man in the row behind. And that was only after the first movement of George Enescu’s massive Symphony No. 3, one of the most remarkable effusions by the composer and crack violinist chiefly known for his pair of Romanian Rhapsodies, popular picture postcards.

Barbara Hannigan, we all know, is game for anything. This Canadian soprano with the pearliest tones and the dramatic instincts of a Sarah Bernhardt can find beauty and meaning in almost every contemporary composer’s barbed wire. Recently she’s been cavorting on stage as Alban Berg’s Lulu; earlier this month, for a sliver of Ligeti, she paraded herself on the Barbican platform as a gum-chewing schoolgirl in a naughty micro-skirt.

To pair Rachmaninov’s brooding and little-performed The Miserly Knight with Wagner's brooding but much-performed Das Rheingold is an audacious piece of programming. The operas share an interest in the mortal power of money, and Rachmaninov’s score has a more distinctly Wagnerian colour than much of his later work. To do so in a single evening, requiring substantial cuts to the score of Rheingold, and to stage them in the Royal Festival Hall, shows boldness verging on the reckless.

James Dillon calls this major work, premered at the Huddersfield Contemporary Music Festival last November, a “Cubist Stabat Mater”. He sets the hymn, but adds in more recent words, texts on related themes by Picasso, Kristeva and Rilke, among others. The music, too, acknowledges the passage of historical time, with subtle references to musical styles from down the centuries. If this all sounds like a recipe for Postmodern intellectualism and detachment, the results are surprisingly direct – a heartfelt and emphatic response to the image of the grieving mother.

The Simón Bolívar orchestra is the musical answer to the question “Would you like to supersize that?” A youth orchestra in bulk, if no longer in name, the ensemble has made a signature of its heft, making repertoire work on its own terms rather than adjusting itself to fit. On Thursday night, full-fat Beethoven and Wagner that threatened to overspill in the generosity of their gestures, so how would the orchestra fare with Mahler’s mighty Fifth Symphony?

Youth may have vanished from the title, and its first flush is gone from the cheeks of most of the young persons. Now they’re in their prime, a magnificent sight – and the sound, too, is that of a world-class orchestra with a voice. Which we heard at its most distinctive, deep and muscular, from the strings in the opening signals of Beethoven’s Fifth Symphony. So what went wrong with the music from Wagner’s Ring in their first 2015 Southbank concert’s second half?