LONDON — They mourned. They memorialized. They moonwalked.

From across the globe, the tributes poured in Friday to Michael Jackson from fans who found it hard to believe that the King of Pop, a star for most of his 50 years, was no longer among them.

He was one of the most famous Americans on Earth — certainly, with one possible exception, the most famous African- American, his face recognized in even the remotest of corners. But where President Obama gets treated like a rock star by adoring crowds around the world, Jackson actually was a pop rock star, one whose music transcended borders and meant more than just dance-able tunes to legions of listeners.

“There are very few American artists or bands I am used to listening to, but Michael Jackson was definitely among them,” said Hany Mwafy, 28, a dentist in Cairo. “Jackson simply symbolized the whole Western culture and music for us. American pop for us was all about him.”

It was the same in Russia, once cut off from the West by the Cold War but exposed to Jackson through bootleg cassettes and videotapes.

“His songs connected our generation to the United States,” said Larisa Bershotskaya, whose grown-up son spent chilly winter afternoons as a boy copying Jackson’s dance moves from music videos. “My entire family has deep, deep love for him.” Misty-eyed, the 50-year-old gymnastics teacher added her bouquet of flowers at an impromptu shrine to Jackson outside the U. S. Embassy in Moscow.

In Mexico City, dozens of Jackson fans hurried to the famed Angel de la Independencia monument, an all-purpose gathering spot on the city’s scenic main boulevard. Dressed in Jackson-style black fedoras and trademark reflective sunglasses, they sang his hits and placed candles and photographs at a makeshift shrine.

Another tribute sprang up on the square in front of Notre Dame Cathedral in Paris, where knots of people engaged in sobbing group sing-alongs and gathered around break dancers and Jackson impersonators.

Holding up posters, wearing single white or silver sparking gloves and black fedoras, they sang along in their best English accents and danced furiously to the faster tunes.

In London, thousands of people struggled to deal with the double loss of Jackson and of the chance to see him perform again after a decade’s hiatus. The singer was booked to appear at the O2 Arena in a few weeks’ time, for the first of 50 planned concerts at the venue.

Tickets for all the scheduled dates—nearly a million in total — were snapped up within hours of going on sale. On Wednesday, promoters had announced that extra seats were available by lottery. But barely 24 hours later, Jackson was dead.

As envisioned by Randy Phillips, chief executive of AEG Live, the concert promoter behind Jackson’s comeback, his 50 dates in London would have been the first of a four-phase plan to have the singer tour the world, hitting Europe and Asia — including India, Australia, China and Japan — before returning to North America.

The tabloids that had baited Jackson mercilessly when he was alive, dubbing him “Wacko Jacko” for his erratic behavior, increasingly strange looks and accusations of child molestation, were suddenly effusive in their praise of a man “who provided the soundtrack to a billion lives.”

“The whole world was his stage and the whole of mankind his audience,” the best-selling Sun said in an editorial. “Those lucky enough to have seen him will never forget it. Those with his records — and can there be anyone who hasn’t got his records — will play them today and weep.”