Two numbers, one hair-raising slice of music-theatre. When Sondheim's paying homage to the older, revue type of musical, you can extract a string of top hits: Follies, from which Marianka Swain chose "I'm Still Here" yesterday, could yield at least half a dozen more choices, Company almost as many. When his aim is a more through-composed kind of story-telling, with leading motifs recurring and transformed, "highlights" are less easily detached.

Surely there’s never been a more apt time for Sondheim’s great cry of defiance? “I’m Still Here” is sung by showgirl-turned-actress Carlotta in Follies (1971) – added during the Boston try-out in place of “Can That Boy Foxtrot”. Loosely inspired by Joan Crawford, it’s the ultimate anthem of showbiz survival.

Here's an irony worthy of the work of Stephen Sondheim, an artist who clearly knows a thing or two about the multiple manifestations of that word. On the same day that he turns 90, namely today, Broadway is unable to host the keenly awaited American premiere, scheduled for this evening, of the gender-flipped Company that stunned London last year.

Two years before he took on The Beatles, George Martin was working with another artiste who would go on to have success in America. Martin first encountered Matt Monro in 1960 when he signed him to the label he ran, Parlophone. The “Portrait of my Love” single charted later in the year. In summer 1961, “My Kind of Girl” hit America’s single’s charts. His 1965 version of ”Yesterday” had a Martin arrangement.

There’s concept on top of concept in this revival of Jason Robert Brown’s beloved 2001 musical, which charts the ebb and flow of a relationship by juggling timelines: aspiring actress Cathy’s story is told in reverse chronological order, while aspiring writer Jamie’s moves forward. It’s an apt framing for a couple who are never on the same page, their dual ambitions and relative success wrenching them apart.

It’s not so much that Pretty Woman: The Musical isn’t much good, which it isn’t.

The theatre gods rained down not fire and pestilence, but a 45-minute technical delay on opening night of this substantially revised musical – a stage adaptation of the 1998 DreamWorks animated movie. But nothing could entirely halt this juggernaut; fittingly, for a show that earnestly values persistence and the unstoppable power of the epic.

This latest musical theatre exercise in “geek chic” has been an American phenomenon: a show propelled by social media that developed a rabid fan base taking it all the way to Broadway last year.

“Take our country back!” is the rallying cry of the self-identified “real” Americans gathered to protest the arrival of immigrants.

Do you hear the people sing? In recent months, you're more likely to have heard news stories about the longest running West End musical than the actual music. Stephen Sondheim – who celebrates his 90th birthday in March – missed the gala opening of the venue which has been renamed after him (formerly the Queen's), due to a fall – and some Les Mis singers have been pulling out as rapidly as champagne corks.