ENO’s The Rhinegold opens at The Coliseum on February 18

STAGING the four operas that are Wagner’s mighty Ring Cycle is the musical equivalent to building a cathedral, swimming the channel, or sorting out Britain’s post-Brexit economy: an epic undertaking that as often as not fails. And when English National Opera’s new Cycle started turning last year, it looked so like a dud – with lousy sets, worse costumes, and banal production values from director Richard Jones – that many thought it would get ditched.

But ENO stood firm. And with a resolve that’s been strengthened by the company’s (temporary) reprieve from collapse at the hands of the Arts Council, it’s going ahead with the next instalment, The Rhinegold, which opens Feb 18 and may hopefully be better.

Rhinegold is in fact where the story of the Ring starts: a mythic tale of gods, heroes, dungeons and dragons that’s effectively the precursor of every grand folk-loric fantasy series ever seen onscreen – including Lord of the Rings which is to some extent an elaborate rip-off.

That no one can definitively tell you what the Ring is about is a gift to stage directors, who accordingly claim licence to do as they please with it. But in the broadest terms it’s the history of a world – perhaps our own – hurtling toward destruction thanks to a terminal combination of greed, delusion and vanity (though “hurtling” may not strike you as the right word when you’ve sat through the collective 16-17 hours that the operas take to unfold).

Rhinegold is in fact the shortest: over in flash, comparatively speaking. And however awful it looked, ENO’s previous instalment – Valkyrie – was actually well sung. So don’t be put off: it could change your life (Ring Cycles sometimes do). Runs to 10 March. eno.org

Dvořák’s Rusalka isn’t usually a life-changing experience, but its poignant story of a water-nymph who loves a mortal and suffers the consequences is touching, and the score contains one of the loveliest soprano arias in all opera. So consider the new production opening at the Royal Opera House on Feb 21 a diary date.

It’s being staged as a fable about human interference with nature. And the participants are impressive – conducted by the masterly Semyon Bychkov whose long-established career seems to be riding higher than ever these days, with soprano-of-the-moment Asmik Grigorian as the nymph and Dame Sarah Connolly camping it up (I would imagine) as the witch Jezibaba. Runs to Mar 7. roh.org.uk

• The annual London Handel Festival opens Feb 23 with a performance of Alexander’s Feast which describes how Alexander the Great is so moved by the power of music he feels compelled to burn down the city of Persepolis. A warning to us all. It plays at St George’s Hanover Square where, last time I walked past the church, its portico was collapsing. Take a hard hat. london-handel-festival.com

• Two years ago the Orchestra of the Age of Enlightenment – one of the world’s great period bands – based itself in Tufnell Park’s own Acland Burghley comprehensive school; and the relationship has been productive on all sides, with projects that continue on Feb 18 when members of the band run an event to introduce toddlers to classical music. Could be bedlam, could be wonderful. oae.co.uk