(Photo: The Graham Norton Show)

The latest season of The Crown features some wince-inducingly tense exchanges between various members of the British Royal Family and '80s Prime Minister Margaret Thatcher, but this doesn't appear to have stopped from the cast from having fun on set.

Gillian Anderson, who plays "the Iron Lady" in the new season, has shared a behind-the-scenes video of the cast breaking into an a cappella rendition of the traditional pop classic "Mr. Sandman."

Helena Bonham Carter (Princess Margaret), Marion Bailey (Queen Elizabeth the Queen Mother), and Erin Doherty (Princess Anne) are all super-enthusiastic from the start, whereas Olivia Colman (Queen Elizabeth II) and Tobias Menzies (Prince Philip) need a second or two longer, perhaps, to find their rhythm.

Anderson captioned the video "a Royal jam" and shared it on Twitter here.

The latest season of The Crown premiered on Netflix earlier this month and is the last featuring the current cast. Season five, expected in 2022, will introduce Imelda Staunton as Queen Elizabeth II, Lesley Manville as Princess Margaret, and Elizabeth Debicki as Diana, Princess of Wales.

There's still no word on who will play Prince Charles and Prince Philip in season five, which will be the penultimate installment of the lavish drama series following the British Royal Family from Queen Elizabeth II's ascendancy to the throne in 1952 until at least the 1990s. It's not yet known, though, whether writer-creator Peter Morgan intends to continue dramatizing the British Royal Family's story any closer to the present day.

You can also watch cast-mates Olivia Colman and Helena Bonham Carter having fun together on The Graham Norton Show below:

What do you think of The Crown cast's singing skills?