Gaga and Bennett, Royal Albert Hall

He’s a traditional crooner with six decades under his belt, tagged by Frank Sinatra as “the best singer in the business.” She’s a pop eccentric better known for wearing a dress stitched together from raw meat than a respect for music past. Yet after a backstage meeting at a charity gala, Tony Bennett and Lady Gaga decided to collaborate on an album. Cheek by Cheek takes eleven jazz standards by the likes of Cole Porter, Irving Berlin and Duke Ellington and transforms them into elegant duets. With astounding sales in the US, the record has brought the music of 1920s and 30s America to a new audience.

Now, in a rare live appearance, they are heading to London’s Royal Albert Hall for one of the best London concerts, 2015. All proceeds will go to Wellchild, helping seriously and terminally ill children. With both an orchestra and a big band present, and a further selection of hits from both artists’ back catalogues, it promises to be quite a spectacle.

Lady Gaga burst into the pop world in 2008 with an inexorable run of hits. Tracks like ‘Poker Face’ and ‘Just Dance’ became quickly ubiquitous in clubs, shops and on the radio alike. Journalists obsessed over her flamboyant costumes, artistry and apparent mystique, while a loyal fanbase – her self-styled 'Little Monsters’ – bolstered her into an unstoppable phenomenon. Now with four solo albums under her (doubtlessly outlandish) belt, she has become a steady fixture of the pop scene.

New York-born Tony Bennett was drafted into the U.S. Army in 1944, and fought through Germany in the final months of the Second World War; the experience led him to become a lifelong pacifist. After a spell as a waiter – during which he would serenade customers at the table – a 1950 demo saw him signed to Columbia Records. With a steady stream of hits and an ever-growing musical depth, his career soared for a decade and a half. After a rough patch in the 70s, with his music perceived as out-of-fashion and a cocaine addiction, he revitalised his reputation. He has recorded music and toured ever since.