Maybe you can't compare incomparables, but it was instructive to watch this Broadway lockdown gala feting nonagenarian Stephen Sondheim a night after the Metropolitan Opera's galaxy of stars welcoming us into their homes.

“Whipped cream with knives” is how Harold Prince, who directed the Broadway premiere of A Little Night Music in 1973, famously described this particular Sondheim show. And nowhere is that borne out with more exquisite agony than in this duet between two unhappily married women.

Ever since I heard the quintessential prog rock group The Nice do a psychedelic instrumental version of “America” in 1968, I have loved this song. Later on, I was better able to appreciate Sondheim’s lyrics, whose satirical sharpness and superb inventiveness make this the definitive song about migration.

Along with many others, my first exposure to Stephen Sondheim’s art was through watching the film of Bernstein’s West Side Story as a child. The song which still floors me is the Quintet near the end of Act 1. Bernstein’s ecstatic, dynamic music is  splendid in itself, but the number’s perfection is sealed by Sondheim’s lyrics, each character distinctly voiced, the rhythms and rhymes flawless. “Sperm to worm,” still makes me grin. That ability to articulate different voices, to overlay disparate musical styles is a trademark.

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.

“Every now and then the country goes a little wrong”: so goes one of the many lyrics from the Stephen Sondheim-John Weidman musical Assassins that makes this 1990 Off Broadway musical (subsequently chosen to open Sam Mendes’ Donmar Warehouse in 1992) a piece of theatre very much for our time. Some shows need textual tweaking when they come around again but not this one.

This is a golden age of London Sondheim revivals, with Marianne Elliott’s thrilling Company still playing in the West End, and Dominic Cooke’s Follies getting a hugely welcome second run at the National – both testament to a director’s transformative vision.

Will pride of place amongst theatre productions every year go in perpetuity to the work of Stephen Sondheim?