It's not a milestone known to many, but 30 years, 9 months and 16 days have elapsed since Pink Floyd launched a world tour in Los Angeles to promote its concept album "The Wall."

The project's mastermind, Roger Waters, recalled the historical tidbit during his return engagement to the city on Monday, which also coincided with the 31st anniversary of the album's release in Britain.

Since the 1980 tour required an 80-man crew and the props cost nearly $1 million, according to the music-industry expose "Hit Men," the rock band limited the multimedia extravaganza to four stops: Los Angeles, New York, London and Cologne.

Waters, 67, long departed from Pink Floyd after a nasty spat with his bandmates in the mid-1980s, is now sparing no expense bringing "The Wall" to the rest of the world.

The North American leg began in Toronto on September 15, a three-month European jaunt kicks off in Portugal in March, and an Australian swing may happen in late 2011 or early 2012.

Each show sees a giant wall slowly rise between the 12-man band and the audience as Waters performs his autobiographical songs of disillusionment, including Pink Floyd's biggest hit "Another Brick in the Wall, Part 2."

DEATH, DESTRUCTION

A Spitfire airplane crashes into the stage at one point, a radio-controlled pig rises above the crowd with political slogans scrawled across its belly, grotesque puppets sway ominously to an unrelenting blast of light, sound and video.

The two-hour concert is a harrowing journey through death, destruction and despair. Photos frequently flash across the wall of victims of violence, including Neda Agha-Soltan, whose killing during the 2009 Iran election protests was broadcast over the Internet.

Waters also screened the leaked U.S. military video showing two Reuters news staffers being killed in a 2007 attack by Apache helicopters. "Namir Noor-Eldeen and Saeed Chmagh, we will remember you," a banner read.

At his request, fans sent in pictures and reminiscences of loved ones lost to war and terror, including both Allied and German soldiers from the world wars. Their bios appeared on the wall during the intermission.

"The Wall," a double-disc album that remains one of the best-selling releases of all time in the United States, was inspired in part by Waters' own wartime tragedy. His father was killed in action during the Second World War.

If the audience at Los Angeles' Staples Center was left in a somber mood, Waters at least seemed to enjoy the experience. He admitted that his rendition of "Mother" to video and audio footage of him performing the same song in 1981 was "somewhat rather narcissistic."

As he left the stage, he told the crowd he had taken a long journey from the "isolation and disaffection and disappointment" that drove him to create the album. Now, he was "happy" and "feeling the love."