So, what, after all, do Andrew Lloyd Webber and Stephen Sondheim have in common apart from their birth date? As last night's rapturously received opening of Sweeney Todd at the Adelphi thumpingly confirmed, they both come over all Verdian, Rigoletto-style, in the last gasp of their respective musical near-masterpieces, Love Never Dies and the demonic barber fable.

Which is not something I was expecting to ponder at the end of a highly theatrical day when the Queen addressed parliament in Westminster Hall on the occasion of her diamond jubilee while I joined the queue at a sneak preview of the refurbished Kensington Palace.

The palace, and its newly landscaped gardens, re-opens to the public next week after a £12m major renovation project. There's a special new Queen Victoria exhibition -- "Victoria Revealed" -- for the jubilee year, including newsreel footage of Queen Victoria's own diamond jubilee in 1897; and a witty, subtle occupation of the state apartments by theatre-makers Coney, who've done this sort of installation work before with Tate Britain and the Science Museum.

These state apartments were at the centre of royal and political life in the 17th and 18th centuries, and Coney bring them alive with specially designed cushions, whispers in the walls, some striking collages and paper cut-outs, all conceived in collaboration with Whatsonstage.com award-winning designer Joanna Scotcher.

In the Queen's Apartments, which are intimate and wood-panelled, we read about, and overhear, the rise and fall of the Stuarts through the consciousness of young Prince William, the future king who danced himself to death on his eleventh birthday. There are magic mirrors and spooky soundscapes, and a magnificent family tree, made of small illuminated caskets, in the Queen's bedroom.

The King's Apartments are much grander and more lavishly decorated, with a wonderful musical clock as a centrepiece. Moving to a place of favour in the King's pecking order was the work of a lifetime for the diligent courtier; today's networkers are encouraged by Coney actors in period costume to take a hand of cards and adjust that hand, from room to room, into a winning flush.

You then trade that hand for an identity inscribed on a cabinet of boxes, and you are directed to the next room where you can mingle with your confreres and sit on a cushion embroidered in your new name, listening to the gossip at court in the walls.

It's all very informative and enjoyable -- I had the great pleasure of going round with Time Out's discreet and clever theatre editor, Caroline McGinn -- and all the time you can enjoy the building itself and the views across Kensington Gardens. This is not a park I've penetrated before (apart from last year's extravagant Peter Pan production), even though I worked for seven years right across the road at Associated Newspapers.

The nearest I ever came to the Duke and Duchess of Cambridge's future abode was the park-facing bar in the Royal Garden Hotel, where I once encountered Shane Warne and the Australian Test Cricket team and was heavily defeated in a Bellini cocktail consumption contest by my late friend and colleague Lester Middlehurst.

Yesterday's press preview attracted no less than 250 journalists and several film crews, and we were easily and comfortably accommodated throughout the public rooms, the attractive new cafe with adjoining garden, leading into the Orangery, and the rather chi-chi new gift shop selling old-fashioned party games and luxury chocolates.

And with an eye on the tourists in the year of the Olympics, there's a new display of five dresses worn by the late Princess Diana -- loaned from someone in Chile, curiously enough -- to complement the other attractions in the adjacent Kensington Gardens: the Princess Diana memorial playground, the Peter Pan statue, the Serpentine Gallery...

You reach the dresses down a small corridor decorated with kindergarten wallpaper, Princess Di's face prominent in the patterning. And, I have to say, she very nearly comes alive again in her Emanuel ball gown, a shocking pink Catherine Walker evening dress and a stunning, sleek little black cocktail number by Versace.

One remarkable and unusual facet of the Queen Victoria exhibition is the way the inscriptions - most of them quotations from the Queen's own letters and diaries -- are sewn into carpets and cushions, and affixed like transparent labels on mirrors, tables and even walls.

Searching hard as I did, I still could find no mention of Sweeney Todd among all the Victoriana and love-struck gush about Prince Albert. Different world. And no meat pies for sale in the cafe, either...