アヴリルに米ビルボード・シングル・チャートでの最初の1位をもたらしたのが「Girlfriend」。アルバム『The Best Damn Things』からのリード・ナンバーで、10か国以上で首位をマークした。世界中で700万以上のダウンロード・セールスを記録し、日本語やスペイン語、フランス語など7か国語で歌ったバージョンも話題を集めた。
LOS ANGELES, CA - FEBRUARY 13: Bob Dylan performs onstage during The 53rd Annual GRAMMY Awards held at Staples Center on February 13, 2011 in Los Angeles, California.
LAS VEGAS, NV - APRIL 03: Singer/songwriter Taylor Swift in the audience at the 46th Annual Academy Of Country Music Awards held at the MGM Grand Garden Arena on April 3, 2011 in Las Vegas, Nevada.
NEW YORK, NY - MAY 27: Lady Gaga performs on ABC's "Good Morning America" at Rumsey Playfield, Central Park on May 27, 2011 in New York, United States.
LAS VEGAS, NV - MAY 22: Singer Beyonce performs onstage during the 2011 Billboard Music Awards at the MGM Grand Garden Arena May 22, 2011 in Las Vegas, Nevada.
LONDON, ENGLAND - MAY 31: Musicians Brian May (L) and Roger Taylor of Queen join cast members on stage during the 9th anniversary performance of 'We Will Rock You' at the Dominion Theatre on May 31, 2011 in London, England.
LOS ANGELES, CA - JUNE 26: Actress/Singer Willow Smith (L) and Actor/Rapper Jaden Smith arrive at the BET Awards '11 held at the Shrine Auditorium on June 26, 2011 in Los Angeles, California.
GLASTONBURY, UNITED KINGDOM - JUNE 25: Chris Martin and Jonny Buckland of Coldplay performs on the Pyramid Stage during the third day of Glastonbury Festival 2011 at Worthy Farm on June 25, 2011 in Glastonbury, United Kingdom.
LOS ANGELES, CA - JUNE 26: Singer Justin Bieber speaks onstage during the BET Awards '11 held at the Shrine Auditorium on June 26, 2011 in Los Angeles, California.
TWIN LAKES, WI - JULY 21: Lady Antebellum L/R: Dave Haywood, Hillary Scott and Charles Kelly perform at Country Thunder music festival - Day 1 on July 21, 2011 in Twin Lakes, Wisconsin.
CARDIFF, WALES - OCTOBER 08: (L-R) Prince Jackson, Blanket Jackson and Paris Jackson appear onstage at the 'Michael Forever' concert to remember the late Michael Jackson at The Millenium Stadium on October 8, 2011 in Cardiff, United Kingdom.