Rush on The Colbert Report Tonight!

NEW YORK (AP) -- Rush will be appearing on "The Colbert Report," and it's not Limbaugh.

The Canadian band Rush, which hasn't performed on U.S. television in more than three decades, will play their classic "Tom Sawyer" on the Comedy Central show Wednesday (11:30 p.m. EST). The Geddy Lee-led trio, which is currently on tour, hasn't played on U.S. television since 1975.

Rush is only the latest act to perform on "The Report," which has steadily edged closer to "Ed Sullivan Show" territory. With increasingly frequent musical performances, "The Report" has grown a variety-show impulse, evident in other upcoming bookings.

The rapper Nas will perform on July 23, Toby Keith will return for a second performance on July 28 and Crosby, Stills and Nash will play on July 30.

The Stephen Colbert-hosted comedy show was originally launched as a parody of conservative political punditry — and shows like "The O'Reilly Factor" do not make a habit of hosting music performances.

But "The Report" circus has expanded into musical realms, often with its sonorous host joining in. John Legend, Neil Young, R.E.M., Tony Bennett, Peter Frampton, Willie Nelson, Barry Manilow, John Mellencamp, the Roots and Carole King have all performed on the show.

Colbert's enthusiasm for the music has been easily apparent. He's sung the Star Spangled Banner (in two-part harmony) with Legend, and mocked the MTV-style band interview by questioning R.E.M. from a stool twice the size of those the band sat on.