Let’s get one thing straight at the outset: Szymanowski’s 1926 opera Król Roger isn’t a lovely occasional oddity, a rarity whose appeal is largely novelty, or a dust-it-off-once-a-decade sort of piece. It’s that rarest of things, a real and original masterpiece whose worth has been unaccountably undervalued. This new production by Kasper Holten does nothing to obscure its beauty, making a strong case not only for the work’s sensual appeal, but also the larger philosophical architecture underpinning this maverick score.

Deep pain and sadness expressed through intense creative discipline aren’t qualities noted often enough in the music of Sergey Rachmaninov. Yet they’ve been consistently underlined, with rigour to match, in Vladimir Jurowski’s season-long “Inside Out” festival with his London Philharmonic Orchestra playing at a consistent white heat.

It took just two bars of Debussy's La plus que lente for Stephen Hough to transport the entire Royal Festival Hall to Paris. The nearest thing the French composer ever wrote to a café waltz – inspired by a gypsy band in a local hotel – this bewitching, louche yet elusive little piece might in other hands make a more suitable encore than opener.

Poised vibrantly enough between the buried-alive monotony of Philip Glass and the dynamic flights of John Adams, Steve Reich’s Three Tales deserves a special place in music-theatre history ("opera" it is not). Ironically, since it deals with the two-edged sword of the 20^th century’s major scientific developments, the video work with which the music interacts so brilliantly – by Reich’s former wife and long-term collaborator Beryl Korot – has been left looking a bit dated by rapid progress in that field since its 2002 premiere.

There can be few modern plays as testing for a female actor as Manfred Karge’s Man to Man. When Tilda Swinton took it on at the Royal Court in 1987 and brought to the many roles of this one woman show her androgynous intensity it was the performance that made her name. Here in Cardiff for the Wales Millennium Centre’s revival, Margaret Ann Bain gives one of the most tireless and faultless performances a Welsh stage has seen in some time; a breathless, kinetically poetic 70 minutes that is never anything less than entirely captivating.

Over the past two Saturdays, Vladimir Jurowski and a London Philharmonic on top form have given us a mini-festival of great scores for Diaghilev’s Ballets Russes.

Pierre Boulez sits in the back of a car as it drives across Westminster Bridge. He is talking about the audience appeal of his music, and he is characteristically direct. If the performance is good, and the situation is right, he insists, then audiences will come. That was back in 1968. The interview was featured in one of the documentaries that began today’s event, and it proved prescient. Boulez at 90, the day-long festival of music by the BBC Symphony Orchestra's former chief conductor, was well planned (by the BBCSO) and well performed.

Serenade seems to be one of George Balanchine’s most evanescent works, a floating, delicate skein of movement that is over almost before it begins, leaving nothing but memory behind. In reality, it is tough as old boots, a warrior of a ballet, one that endures, survives – and enchants over and over.

Reviews of English National Ballet in which I rave about what Tamara Rojo is doing for the company are getting to be the norm round here. This one is no exception, and I'm not even going to apologise for it.  Last night was the opening of Modern Masters, an ambitious new bill in which the company more than prove they're up to handling the big beasts of late twentieth-century choreography.

How do you take your rom-coms? Full-fat Hollywood schmaltz, Shakespearean, or lean and elegant – a Stoppard perhaps, or Coward? If your answer did not include “With lashings of social philosophy, ethics and a lengthy dream sequence, preferably running north of three hours”, then Man and Superman might not be the play for you.