Veteran British rocker Roger Waters -- co-creator of the legendary Pink Floyd album "The Wall" -- performed before tens of thousands of Israeli fans on Thursday, after calling on Israel to tear down massive concrete blocks walling off parts of the West Bank.

An estimated 50,000 gathered in a hastily prepared outdoor venue for the concert next to the Jewish-Arab village of Neveh Shalom in central Israel. Israeli performers warmed up the crowd before Waters began his performance about half an hour behind schedule.

In the hours before the performance, cars were backed up for many kilometers (miles) in all directions in one of Israel's biggest-ever traffic jams.

Waters refused to appear in the usual sites for outdoor concerts in Tel Aviv, citing his opposition to Israel's policies toward the Palestinians, agreeing in the end to the field about halfway between Jerusalem and Tel Aviv.

One of the concert site staff, identified only as Amit, told Israel Radio that monks at a nearby Trappist monastery had given their blessing to the concert and its powerfully amplified message of coexistence, but as members of a silent order, "It's not likely that they'll sing along."

On Wednesday, after arriving in Israel, Waters visited a walled section of Israel's West Bank separation barrier running through the Palestinian town of Bethlehem and spray-painted a line from the album, reading, "No thought control" on the towering concrete blocks.

"It fills me with horror," Waters told reporters at the site. "You can see photographs of something like this, but until you've seen the actual edifice itself and seen what it's doing to these communities...It's hard to comprehend that they could be doing this."

In 1990 he performed music from the album at a site where the Berlin Wall once ran, to celebrate the reunification of East and West Germany.

Israel says it is building the wall to keep out Palestinian attackers. Suicide bombers have killed more than 500 Israelis and maimed many more since the September 2000 outbreak of fighting between the sides.

But because the barrier dips into the West Bank at several points, incorporating West Bank land on the "Israeli" side, Palestinians denounce the obstacle as a front for grabbing territory they claim for a future state.

Waters, 62, said he hoped that like the Berlin Wall, the Israeli barrier would fall.

"It may be a lot harder to get this one down, but eventually it has to happen, otherwise there's no point being human beings," he said.

Israel says the half-finished, 760-kilometer (470-mile) barrier will be 95 percent electronic fence and only 5 percent wall when complete.