After a critically panned venture into American blues with "Rattle and Hum, " U2 left behind the world of anthem rockers and ballads and moved into a new era of musical experimentation and self-awareness of their own success.

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One of their biggest hits was "Boogie Woogie Bugle Boy, " which became a World War II anthem.

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She topped the bill at the opening of the Welsh Assembly in 1999, and performed the anthem World In Union with Bryn Terfel for the Rugby World Cup in 2000.

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Lastly, and perhaps most notably, I once sang the national anthem at a World Series baseball game, though I was not in the vicinity of the microphone at the time.

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The first three national anthem singers at the World Series were country artists: "American Idol" winner Scotty McCreery, Trace Adkins and Ronnie Dunn (of the former Brooks and Dunn).

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