DiDonato/ Calleja/ Hampson/ Vassilev/ Pappano, Royal Opera House, London

Only the Royal Opera House could lose one star (the indisposed Dmitri Hvorostovsky) and find three others; well, five actually since Antonio Pappano, the evening's inspired accompanist, brought with him his orchestra's concert master, Vasko Vassilev, serenading us with Tchaikovsky and Rachmaninov in so homespun a manner as to turn a public concert into a private soirée.

Truly, this hurriedly prepared concert party felt so deliciously informal and spontaneous that you could only wonder at how such diverse material had been assembled with such diligence and at such speed. The answer, of course, is Pappano whose hands-on stewardship of this house inspires artists to go the extra distance for him. It is a measure of the respect he commands that Thomas Hampson and Joseph Calleja gave up their time to avert cancellation.

But for all the vocal skill on display here, it was Pappano who modestly, discreetly, dazzled at the piano. His unfailing musicality and sense of style is what makes him such an outstanding music director and here he was exemplifying just such attributes at the keyboard, effortlessly straddling a repertoire from five different nationalities with self-effacing deftness and insight.

Here, he twinkled and sashayed around Joyce DiDonato as she teased out the dusky charms of "Can't Help Lovin' Dat Man" from Kern and Hammerstein's Show Boat. It's amazing just how much a number like this has in common with the enticing come-ons of Rossini's song triptych La Regata Veneziana where the sultry Anzoleta offers her own very particular incentives to her dreamy oarsman. There was more Rossini with DiDonato limpidly navigating the arabesques of the "Willow Song" from Otello.

Thomas Hampson gave us Mahler's Lieder Eines Fahrenden Gesellen still, after all these years, retaining the rapture of youth through the honeyed legato of his trademark head-voice and Joseph Calleja showed off his warm, well-upholstered, tenor in a series of Italian and French bonbons. How he nailed Rodrigue's aria from Massanet's Le Cid. He and Hampson could not have escaped The Pearl Fishers duet – they nailed that, too, the blend of timbres reminding us why they make such a convincing father-and-son act in Traviata. Pure pleasure.