Cadogan Hall’s now regular series of celebrations of the work of the great songwriters began some three years ago with a tribute to Stephen Sondheim. The composer’s 80th birthday now provides an opportunity for the same forces to revisit these masterpieces of musical theatre.

Maria Friedman, Daniel Evans and Graham Bickley were joined once again by the Royal Philharmonic Orchestra under David Firman for a tighter programme than the 2007 concert, stripped of commentary and allowing the music to speak for itself.

The evening began with a potted version – some 50 minutes – of Sondheim’s brashest score Merrily We Roll Along. Projections helped us find our way through the tricky dramatic structure as time winds backwards, and many of the show’s best numbers peaked with Daniel Evans’ brilliant rendition of “Franklin Sheppard Inc”.

After such a generous dollop of one of the lesser-performed shows, the 90 minute first half continued with a smattering of other works with the simpler accompaniment of double keyboards. There was a nice joke for Company’s “I’m Not Getting Married Today”, with Amy becoming Jamie, as the parts were re-distributed among the sexes and the song was brought bang up to date, something not easily imaginable when the show was new in 1970.

Graham Bickley gave a haunting account of “I Remember” (previously delivered memorably by David Kernan in the original Side by Side by Sondheim) from the one-hit TV wonder Evening Primrose. Evans’ gutsy “Giants in the Sky” (Into the Woods) was followed by he and Friedman playfully romping under a bedsheet for the poignantly funny “Barcelona” from Company.

We went into the interval with the ingenious “You must meet my wife” (Bickley and Friedman) from A Little Night Music and “Send in the Clowns” (Friedman), probably Sondheim’s most famous and oft-performed song. You may have heard it a million times before but it’s always a heartbreaker.

For the second half, the full RPO re-assembled and, with Sweeney Todd on the menu, it was needed. Before that, a short medley from Follies, in which we had to imagine the beautiful girls and “Too Many Mornings,” illustrating Sondheim’s knack of incorporating a whole story into one number, here almost unbearably tender and almost as perfect as anything he’s written.

Bickley didn’t go down the Mandy Patinkin route with “Buddy’s Blues” by performing all the parts himself, but a twist was provided by Evans’ ditsy floozy, after which Friedman banged out the unavoidable “Losing My Mind”.

Sweeney Todd was represented by an orchestral suite, with extended “Joanna,” and Friedman reprised her celebrated “Worst Pies in London” to the bemusement of an elderly gentleman plucked from the audience and forced to stooge with hilarious results. One of the composer’s wittiest creations, the dazzling word-play waltz of “A Little Priest” ended the selection from this great work.

So many outstanding hits and musical theatre Everests – “Losing My Mind”, “Broadway Baby” and “Being Alive” given in quick succession – start to look like barnstorming. Such riches need to be earned by audiences and given out of context lose something of their impact but how could they be left out of a compilation like this?

As the 80th birthday tributes gather momentum, and with the RPO on glorious form all evening, this was an enjoyable contribution to this year’s celebration of arguably the world’s greatest musical theatre composer.