The celebrations: Man of the hour walks among his faithful followers

He didn't shake any hands, was surrounded by dozens of secret service agents, and only left his new heated Cadillac for a few minutes. But Barack Obama's first walkabout as US President succeeded in warming-up a crowd which had been shivering on Capitol Hill since well before dawn.

The two-mile journey from the Capitol's Statuatory Hall, where he had eaten lunch, to the "reviewing stand" outside the White House, from which new Presidents enjoy their inaugural parade, was witnessed by an estimated two million cheering spectators lining either side of Pennsylvania Avenue.

It was the most American of spectacles: a gas-guzzling motor vehicle, proceeding at walking pace, along a route any healthy adult would be perfectly capable of walking. Roughly 100 flashing police cars and motorcycles followed. The entourage was completed by two floats, carrying rolling news teams.

Onlookers hoping for a proper glimpse of the new President and First Lady had their wishes briefly granted when his Cadillac – a bullet-proof behemoth dubbed "The Beast" - paused close to Freedom Plaza. To hysterical cheers, the smiling couple emerged, before waving as they walked a few hundred yards.

When the minus four degree temperatures became too much, the Obamas returned to their vehicle and were slowly driven the remaining distance to their destination. There they joined 300 guests to watch the parade, which featured ninety marching band and was scheduled to last two hours.

For the crowds, it was a fitting centerpiece to a day that had previously seen a poet, a preacher, four classical musicians, and America's greatest living soul diva handed the task of de-frosting them during the inauguration ceremony.

The formal business of oaths and speeches was delivered in tandem with a selection of readings and performances that were intended to add an element of fun to the pomp and circumstance surrounding the inauguration of America's first black President.

Aretha Franklin stole the early part of the show, belting out a note-perfect reworking of "My Country 'Tis Of Thee" in a gospel style that managed to strike a perfect balance between tub-thumping patriotism and schmaltz.

The 66-year-old Queen of Soul looked magisterial as she serenaded the crowd, wearing an enormous overcoat topped by a grey hat with a diamond-encrusted bow and drawing virtually the entire audience to its feet in noisy applause.

Immediately beforehand, Pastor Rick Warren, a televangelist who founded the Saddleback mega-church in Orange County, California, had kicked off the proceedings with a religious "invocation".

Mr Warren's selection for the job had caused controversy when it was announced last month, because he vociferously supported California's recent ban on gay marriage. Perhaps as a result, he drew a half-hearted reception, even during his lively rendition of The Lord's Prayer.

He wasn't the only man on the swearing-in stand who got a hostile reception. TV news footage which surfaced on YouTube later in the day showed outgoing President George Bush getting hissed and booed at by large sections of the crowd.

A classical quartet got the ceremony's prime spot, between the swearing-in of Joe Biden and Barack Obama. They performed a new piece by John Williams the composer best known for having written the themes to Star Wars, Indiana Jones, and Jaws.

The group contained perhaps the world's two best-known classical musicians, the cellist Yo-Yo Ma, and the violinist Itzhak Perlman, accompanied by Gabriela Montero on piano and Anthony McGill on clarinet.

They performed a specially commissioned track called "Air and Simple Gifts", which, in the words of Williams, centred around "an exuberant rendering" of "The Gift to Be Simple," a traditional Shaker hymn that featured in Aaron Copland's 1944 ballet, Appalachian Spring.

The performance of the piece was intended to right a historic wrong: Copland's "Lincoln's Portrait" was to have been performed at Dwight Eisenhower's inauguration in 1953 but was banned at the last minute amid complaints about his liberal politics.

Yet despite the historic pertinence, it seemed to fall flat. The piece would have been perfect for a concert hall, but Washington's blustery winter air carried away many of its subtleties.

Earlier reports stated that Perlman and Ma were worried about the outdoor venue, and had pre-recorded a performance of the track, in case the weather interfered with their instruments. In the event, they were probably right to be concerned.

At four-and-a-half minutes long, "Air and Simple Gifts" seemed to drag, too – a fate also suffered by Elizabeth Alexander, who was handed the poisoned chalice of writing and delivering the inauguration poem.

Mrs Alexander, who is a friend of the Obamas and an African-American professor at Yale, is a fine poet. But her lengthy piece drifted into pomposity, and provided a reminder of the struggles often faced by poet laureates and other writers who are asked to deliver verse to order, to jollify events of national significance.