On August 1, 2007, Prince kicked off a 21 night sold out residency at London's 20,000 seat O2 Arena.

Prince and his band and dancers were in-the-round performing on his giant symbol. General admission tickets were just 31.21 British pounds (about $40).

And after 19 of those nights, he jogged over to the more cozy O2 Indigo Club whose capacity was a mere 2,500 and played a full set at the after party.

This was the fascinating Earth Tour where Prince provided buzz to his new cd, Planet Earth, by including it free in 3 million Sunday newspapers in London two weeks before his first gig there.

Record stores were outraged, but newspaper subscribers were thrilled. Prince laughed all the way to the bank because even at the relatively discounted price of the tickets, he would be performing to over a half million Londoners and many millions had his new music.

Preceding the residency Prince held a press conference and said he and the band were going to play different sets every night and had learned over 150 songs and many covers.

He specifically mentioned an Amy Winehouse song and said he hoped she made it to a show, and if she did he would love to sing with her.

He also said after the tour he'd like to travel and study the Bible.

The next day Amy was being interviewed and hadn't heard about Prince's plans or desire to sing with her, so when the interviewer filled her in, her reaction was genuine and adorable.

"I'm going to Minneapolis, see you later," she joked and pretended to run off.

It was no joke. At the last after party show, Amy joined Prince on stage for the first song of the set. And indeed it was her song "Love is a Losing Game."

Prince's choices of covers was diverse in so many ways. From the Beatles to Dylan to Zeppelin.

Here are the top 21 most-played covers he played with his band during that 21-night stand at the O2 Arena:

Play That Funky Music by Wild Cherry (11)
What a Wonderful World by Louis Armstrong (11)
Crazy by Gnarls Barkley (10)
Le Freak by Chic (9)
A Love Bizarre by Sheila E. (6)
Nasty Girl by Vanity 6 (6)
Pass the Peas by The J.B.’s (6)
Come Together by The Beatles (5)
The One by The New Power Generation (4)
Love Is a Losing Game by Amy Winehouse (3)
All Along the Watchtower by Bob Dylan (2)
Best of You by Foo Fighters (2)
Down by the Riverside by Maceo Parker (2)
Honky Tonk Women by The Rolling Stones (2)
Proud Mary by Creedence Clearwater Revival (2)
Rock Me Baby by B.B. King (2)
Stratus by Billy Cobham (2)
Thank You (Falettinme Be Mice Elf Agin) by Sly & the Family Stone (2)
The Long and Winding Road by The Beatles (2)
Whole Lotta Love by Led Zeppelin (2)
Your Song by Elton John (2)