Luckily for a reviewer, there are nights in the theatre that completely reaffirm your love for the magic of live performance.

Tonight is one of those nights. Maria Aberg’s production of King John is nothing short of a triumph. It is a vital and vibrant reworking of a neglected play that transforms it something funny, thrilling, moving and consistently entertaining.

It is, I will admit, a version of the play that may disturb some purists. Aberg has intelligently reshaped the text (with the assistance of Jeanie O'Hare, the Royal Shakespeare Company’s Dramaturg) and created a performing version which plays perfectly for a modern audience.

Probably the most notable shift is the conflation of the roles of Hubert and the Bastard – and then giving that new role to a woman. Pippa Nixon has been given the part of a lifetime – and she revels in the mischief and wit of the character as well as playing the emotional shifts and inner conflict brilliantly. Outstanding – no other word for it.

However she is not the only brilliant participant in this drama. Alex Waldmann matches her step for step in the title role. Much younger than most to have tackled this tricky role, he grasps it with both hands and gives it a humour and muscularity that is engaging, clear-sighted and always watchable.

[W@S_IMG]#http://whatsonstage.com/images/KingJohn_RSC_apr2012_360.jpg#360#240#Alex Waldmann in King John. Photo credit: Keith Pattison[/W@S_IMG]There are many stand-out performances in the rest of the cast: Paola Dionisotti relishes every word as Cardinal Pandulph – manipulating and oozing her way round the stage. The rest of the women are equally well-characterised – Susie Trayling (capturing the vengeful and heartbroken Constance perfectly), Siobhan Redmond (powerful and strong as Elinor) and Natalie Klamar (finding great depth and humour as the conflicted Blanche). The men are not to be completely outshone – with Edmund Kingsley and Oscar Pearce making notable contributions throughout (as do the entire cast to be fair).

I am loathed to give away too many details of the actual production as there is much to enjoy from seeing this playful interpretation happen in front of your eyes. The setting takes you straight to a party in a modern hotel and from there the action never ceases to surprise or delight you. It is as inventive (if not more so) as last year’s Merchant of Venice. And as with that production, this makes great use of music and dance – but again I will not spoil the delights future audiences have in store. Though perhaps I could say that "I had the time of my life."

This is audacious, exuberant and thought-provoking theatre-making from a director with a clear vision and a company prepared to support and encourage her creativity. This is exactly what the RSC should be doing - long may that continue.

I cannot recall having gasped with delight so many times in the course of an evening in the theatre. And the balloons are a triumph!

- by Simon Tavener