Cyrus, Hudson to perform at gala
US music executive Clive announced that Miley will perform at his annual party during an interview, as will four-time Grammy nominee Lorde.
The 81-year-old also teased a surprise performance by a music legend.
Jennifer called the experience "a dream", but acknowledged that she is nervous to perform for the A-list crowd.
The Grammy Awards take place on January 26 at the Staples Centre in LA.