Roger Waters made headlines earlier this year when he announced plans to revisit “The Wall” on an international tour beginning later this year. But the former Pink Floyd bassist won’t be the only member of the iconic British rock band on that journey.

On the afternoon of July 14, Waters announced on his official Facebook page that Pink Floyd frontman David Gilmour would join him on tour. The special appearance will occur during a single show, with Gilmour providing his vocals for the iconic song “Comfortably Numb.”

It is unknown whether Gilmour will appear on the tour’s fall 2010 leg or spring 2011 leg. According to Waters’ statement, his former Pink Floyd compatriot “will decide in due course which gig he wants to do” and that “it will be a surprise!”

In all, Waters’ itinerary boasts more than 90 concerts, any of which could feature Gilmour’s appearance.

The special appearance is part of a deal that Gilmour reportedly struck with Waters: If the bassist would appear alongside him for a tongue-in-cheek cover of The Teddy Bears’ “To Know Him Is To Love Him” during a July 10 benefit concert for The Hoping Foundation, he would return the favor and play “Comfortably Numb” on Waters’ tour.

“How could I refuse such an offer. I couldn’t, there was no way. Generosity trumped fear,” Waters said of the exchange, adding, “I agreed and the rest is history. We did it… End of story. Or possibly beginning.”

Presales and public onsales for Waters’ U.S. and Canadian tour generated impressive levels of interest among ticket buyers. The acclaimed musician topped TicketNews’ exclusive event rankings for two consecutive weeks — the week ending May 9 and the week ending May 16.