There are some wonderful things in this exhibition, and that’s no surprise: the British Empire endured for over 500 years and at its peak extended across a quarter of the world’s land mass. Preparing an exhibition of corresponding reach must have involved considering a vast range of objects, but choosing well is another matter entirely.

“The first section, following a short introduction, places a rhythmic sequence on its retrograde. The two layers are transposed independently (one going up, the other down) as the music progresses, and points of symmetry are highlighted when they occur”. No, me neither. Apparently Patrick Brennan’s Polly Roe also features a brief rhythmic quotation from Birtwistle’s Carmen Arcadiae Mechanicae Perpetuum. More erudite ears may have been able to detect it.

What dancemaker wouldn't want to tackle Le Sacre du Printemps (The Rite of Spring) at some point? Just as the Stravinsky score changed music, the original Ballets Russes production changed dance - and was then, conveniently, so completely forgotten that no master-text exists. Everyone is free to take the Stravinsky and run. Or rather, dance: as Michael Clark has observed, one of Sacre's gifts to a choreographer is the in-built necessity of dance to the scenario, in which a victim is chosen by a crowd and forced to dance to his or her death.

Sculpture that moves with the gentlest current of air! Sculpture that makes you want to do a little tap dance of joy! Or maybe the Charleston – swing a leg to those sizzling Jazz Age colours and shapes and rhythms. Look, that’s the queen of the Charleston right there – the “Black Pearl” of the Revue Nègre, Josephine Baker. She’s a freestyle 3D doodle in space, fashioned out of wire: spiral cones for pert breasts, that sinuous waist described by a single serpentine line. What a callipygous shimmy. And who’s that with the Chaplin moustache?

Switching between the orderly and the chaotic, David Jones’ depiction of Noah’s family building the ark immerses us in the drama of the moment while simultaneously holding us at some point out of time, to emphasise the story’s ancient roots.

Kim Longinotto’s Love Is All stitches together short extracts from 75 different films, aiming to highlight changing British attitudes to love, sex and romance. It opens with a one-minute 1899 short which looks forward to the closing shot of Hitchcock's North By Northwest, and the final montage includes scenes from My Beautiful Laundrette and news footage of a same-sex wedding in 2014 Islington. It’s frequently a frustrating viewing experience: the short running-time means that most of the clips are just too brief.

There’s no sign of Oldenburg, Warhol or Lichtenstein and British pioneers Eduardo Paolozzi and Peter Blake are notably absent from this gritty vision of Pop art. Only in the final room do we come face-to-face with a Campbell’s Tomato Soup tin, the comforting bright colours and clean, supermarket-aisle lines blackened, singed and fragmented as if salvaged from some unimaginable disaster.

It’s a pleasing serendipity that while Martin McDonagh’s clamorously anticipated Hangmen opened at the Royal Court last night, just a little further west T.S Eliot’s The Cocktail Party should also be having its opening night. Back in 1956 another Royal Court premiere – John Osborne’s Look Back In Anger – called time on Eliot and his dramatic ilk, ushering him into a neglect from which he has never really recovered. But now, sitting once again alongside a younger, more daring breed of theatre, Eliot’s drama proves that – given a chance – it can hold its own.

From its title, you could be misled into dismissing this show as narrow and self-referential: a small exhibition in a small gallery curated by a Belgian artist concerned only with his own countrymen. In fact, it is something of a survey, featuring works with influences that range from Piet Mondrian, Ad Reinhardt and Lucio Fontana, to the Color Field painters.

You can see the logic to the programming of this year’s Free Prom: famous opener with a good tune (Saint-Saëns’s Danse Macabre) to help wash down the new commission (Guy Barker, The Lanterne of Light), before we all get down to business with a nice choral shout (Carmina Burana). If that sounds cynical it’s really not intended to – getting this annual gift of an event right is crucial to the future of the festival itself, reaching out to the classical undecideds and getting them in to make up their own minds.