“A tonic to the nation”. That was the hoped-for effect of the Festival of Britain in 1951, and its concrete legacy was the Royal Festival Hall. Seventy years on, it’s fitting that English National Ballet should be the first through its doors, post Covid closure, with the offer of another kind of pick-me-up – a summery, free-spirited, generous ballet gala which has something for everyone.

The Royal Albert Hall – 150 years old this year and with a commemorative £5 coin to prove it – is a great  space for many kinds of spectacle but has done few favours for ballet. I make an exception for Derek Deane’s in-the-round Swan Lake, if only on the grounds of its having been seen by 750,000 people many of whom might never have set foot in an actual theatre.

People often ask why it is that in ballet there are different casts on different nights, a practice alien to opera, musicals and theatre. The most obvious reason is practical. Ballet companies keep a number of principal dancers on salary who need regularly to strut their stuff. Another reason is that dancers develop distinct individual qualities – technical, musical and dramatic – which imprint on the works they dance.

Did you wonder what all those creative musicians and artists did when they couldn’t perform in public last winter? Some of them started making films. Putting film of yourself online was, after all, a way of communicating with an audience, and had the bonus of being a potential promotional shop window for your work once people were allowed back in venues again.

The Royal Opera House wasn't taking any chances when it welcomed its first ballet audience since December this week. There was no printed programme on offer, nor even a cast sheet. “Not till October” said the uniformed man on the door. Some ballet companies have learnt the hard way not to trust that newly lifted lockdowns (lockups?) will stay that way for long. They’re in no hurry to spend time and money on printed material that might end up having to be pulped.

You could hardly call this back to normal at London’s premier dance house. For a start, there was too much red plush visible in the stalls, not all of it the result of COVID-safe spacing.

It’s official. Masks are coming off across America while theatres remain dark. Over here, theatres are about to re-open and masks must be worn. An identical situation gives rise to different responses prompted by local preoccupations. Local preoccupations are at work in ballet too. Witness the 2021 Spring Gala performance put out digitally by New York City Ballet.

Hard as it is to recall how it felt to sit elbow to elbow in a red plush seat, plenty of us did that during the first 10 weeks of 2020, with no heed at all to who might be breathing over us. I have since wondered what proportion of the dance sector had any inkling of the wrecking ball that was about to hit. None, to judge by the many weeks it took for dance companies and theatres to reinvent themselves online, and to start dredging their archives for decently recorded material.

If dance lovers have learnt anything in recent months it's to take nothing for granted. How could we ever have been so blasé about The Nutcracker, whose annual reappearance in multiple productions was as inevitable as crowds on Oxford Street? As a long-departed dance critic once Eeyorishly observed, each year “brings us one Nutcracker closer to death”, a quip that now has a bleaker resonance than even he can have intended.

Theatres are currently banned from moving scenery and props about on stage and you might expect this to present a major obstacle to a production of The Seven Deadly Sins. How else is the opera’s protagonist to be seen to visit seven American cities, succumbing to a different sin in each? But Opera North’s version of Kurt Weill’s 1933 “sung ballet”, in a new translation of Bertolt Brecht’s libretto, a new orchestration for 15 players and with new choreography by director Gary Clarke, has found unlikely inspiration in the restrictions.