Considering its relatively short time on air, the cast of 'Glee' has racked up some pretty impressive invitations to some pretty important events: They've sung the National Anthem at the World Series; they've been invited to appear at the White House. But that's just small potatoes compared to arguably the biggest show of all: 'Oprah.'

But now, the Ausiello Files is reporting that the queen of all media has invited the cast of the Fox sensation to her Chicago headquarters for an all-out 'Oprah Winfrey Show' 'Glee'-fest next month.

The entire episode will be devoted to all things 'Glee' ,' and will include interviews with the cast and creator Ryan Murphy, never-before-seen behind-the-scenes video and a performance from the cast itself.

To mark this happy event, Winfrey is building up anticipation for the show on her website. Starting the week of Mar. 29, Oprah.com will host a 'Glee' "destination page" where fans of the musical series can gleek out on character bios, I.Q. tests, photo galleries and more.

The 'Oprah' episode is slated to air Apr. 7, which is just a couple days after the cast is scheduled to perform at the White House's Annual Easter Egg Roll.

And of course, all of this is building up to 'Glee' return to Fox on Apr. 13. Mark your calendars, Gleeks, and set your DVRs to record!