By Alison M. Rosen
Updated September 11, 2003 12:43 PM

After announcing their plans to reunite for a North American tour, Paul Simon and Art Garfunkel — rumored to have been embittered with each other for years — will appear for the first time ever on the “Late Show with David Letterman” on Friday.

It will be the legendary folk duo’s first time performing together on TV since their rare performance at the 45th Annual Grammy Awards, where they received a Lifetime Achievement Award for songs such as “Sound of Silence,” “Mrs. Robinson” and “America.”

The reunion tour, which was announced at a press conference in New York Tuesday, will be the duo’s first real tour in 20 years. Called “The Old Friends Tour,” it kicks off Oct. 18 at The Palace in Auburn Hills, Mich., and will travel to more than 30 cities across North America.

For fans needing more gentle folk-rocking, “The Essential Simon & Garfunkel,” a double CD retrospective, will be released Oct. 14.

Simon and Garfunkel, both 61, met as children growing up in Forest Hills, N.Y., and after some stops and starts (they recorded for a time as “Tom and Jerry”) went on to become one of the most successful ’60s folk acts of the era.