God love Christine Baranski: Eight years after the Tony and Emmy-winning actress played the supporting role of Carlotta Campion in a semi-staged 2007 production of Stephen Sondheim's Follies in New York, along came the leggy, eternally lithe performer in the same musical, once again in concert form but this time upgraded to a starring role.

Vaudeville is alive and well in the silvered Lilliputian cave which might have been made for it (not that Victorian Savoyards could have had any inkling). If you find yourself, like last night’s showbiz audience, beguiled to cheering point by the shreds-and-patches routines put together by the ultimate theatrical whirlwind, Mamma Rose, that’s because everything in this London transfer from the Chichester Festival Theatre, parody included, is solid gold. Heck, I’d even have paid to hear the first trumpet in the fabulous wind-and-brass orchestra tune up.

Still they keep coming, 35 years on from the London premiere of Sondheim's "musical thriller": Sweeneys above pubs, in pie shops, concert halls and theatres of all sizes, on the big screen, Sweeneys with symphony orchestras, two pianos or a handful of instruments wielded by the singers, Sweeneys as musicals and as operas, the dumpy and the tall. Which type was this one? Not a vintage English National Opera production, that much seems clear.

Stephen Sondheim's ever-elastic masterpiece is downsized to largely dazzling effect in its latest iteration, which has been transferred intact to a Shaftesbury Avenue pop-up after premiering last autumn within the surrounds of an actual pie-and-mash eatery called Harrington's in Tooting, south London.

Woods and forests were given a fresh impetus as a psychic terrain for the cinema by Lothlórien, Fangorn, and the other sylvan spaces so ethereally or threateningly rendered in The Lord of the Rings films and, to a lesser extent, by the Mirkwood of the second Hobbit movie. All distorted black boles, labyrinths of tangled branches, knobbly roots, and conically sun-strafed clearings, they were movie woods to rival the great Gothic forest of Fritz Lang’s Die Nibelungen: Siegfried (1924) and the magical Athenian wood Warner Bros.

There’s a moment of stunned silence in Imelda Staunton’s storming Mama Rose at the Chichester Festival Theatre, a long, long, moment where neither speaking nor singing she conclusively demonstrates what a difference a great actress makes in this most iconic of musical theatre roles.

“It takes a star to parody one,” wrote theartsdesk’s Edward Seckerson, nailing the essence of this immortal spoof-fest’s last incarnation at the Menier Chocolate Factory. Star quality was assured given the presence of Damian Humbley, peerless in Merrily We Roll Along and even the unjustly short-lived Lend Me a Tenor, who’s in this transfer.

“God,” wrote Stephen Sondheim, “is in the details.” Of course, he didn’t actually coin the phrase but throughout his published collections of lyrics he cites it as one of his three guiding principles. But to witness detail you need to be up close. Last seen on Broadway in the 1,058-seat Barrymore Theatre, Putting It Together felt overblown and strained. In the 312-seat St James Theatre, its strengths – the delights of a deftly interwoven selection of 32 Sondheim songs – leap into focus thanks to a quintet of deliciously detailed performances.

How many times can a director re-work the same show and still come up with something fresh, gripping and memorable? This is James Brining’s third version of Sondheim’s killer thriller musical Sweeney Todd. He produced an award-winning version in 2010 at Dundee Rep. He turned to it again last month for his first production since becoming artistic director at West Yorkshire Playhouse. Now, he has re-worked it for the in-the-round confines of the Royal Exchange, initiating a trans-Pennine collaboration between the two theatres.

On Broadway, Merrily We Roll Along remains forever scarred as the Stephen Sondheim musical that ground to an abrupt halt, closing after two weeks in 1981.