NEW YORK, DECEMBER 18

Mariah Carey is the Queen of Christmas for a reason - and not just because 'All I Want for Christmas Is You' tops the charts seasonally.

Carey has turned the song into an event, regularly hosting Christmas concerts to celebrate her undisputed smash and long career as a holiday icon. This year, she embarked on the 'Christmas Time' tour, a variety show that kicked off on Nov. 6 in Highland, California, hitting many major North American cities, before concluding on Tuesday night at Barclays Center in Brooklyn.

It came to an end in front of a crowd donning shimmery Santa hats and red sequin party dresses. Carey descended onto the stage in a snowflake-shaped throne, leading the audience into a few church staples: 'Silent Night' and 'O Holy Night' among them.

Her children, twins Roc and Roe, joined in on the fun. At one point, Carey detoured into a medley of her biggest hits: 'Emotions,' 'Hero,' 'Fantasy,' and 'We Belong Together' among them.

The latter moment came with an unexpected surprise: the elusive Rihanna was in the audience, and Carey signed her chest during an arena-wide sing-a-long of 'Always Be My Baby.' Ri disappeared as quickly as she emerged, but Carey kept the momentum up, concluding the only way she could - with a spirited rendition of 'All I Want for Christmas Is You.'

Earlier this year, Carey's first Christmas album, 1994's 'Merry Christmas,' turned 30. She told The Associated Press she originally felt apprehensive to record a holiday album and then gave in to the festive spirit.

'I was very young and was just starting out and I felt like people do Christmas albums later in their lives. But now people have started to do them whenever, like right at the top of their career,' she said. 'And I decorated the studio and just had the best time.'