January

• January 8 – Lady Gaga's debut single "Just Dance" hits number one on the Billboard Hot 100 after 22 weeks – the second longest climb to number one, since the Creed single, "With Arms Wide Open", in November 2000 (27 weeks).^[1]
• January 18 – President Barack Obama's inaugural concert, entitled "We Are One", is held at the Lincoln Memorial. Performers include Mary J. Blige, Garth Brooks, Renée Fleming, Caleb Green, Josh Groban, Herbie Hancock, Heather Headley, Beyoncé, Bettye LaVette, Pete Seeger, Bruce Springsteen, James Taylor and Stevie Wonder.^[2] Several of the songs performed had been used by Obama's presidential campaign.^[3]
• January 20 – Artists including Mariah Carey, Jay-Z, Alicia Keys, Faith Hill, Mary J. Blige, Maroon 5, Stevie Wonder and Will.i.am perform at the Inaugural Ball for President Barack Obama^[4]
• January 28 – Kelly Clarkson breaks the record for a song's biggest jump to number 1 on the Billboard Hot 100 when her single "My Life Would Suck Without You" soars from number 97 to number one fueled by 280,000 digital downloads in the first week of release. Clarkson first broke the record in 2002 with "A Moment Like This".^[5]
  • Billy Powell of Lynyrd Skynyrd passed away at the age of 56 at his home in Orange Park, Florida.^[6]
• January 29 – Madonna announces that she will extend her record-breaking Sticky & Sweet Tour during summer 2009, to visit cities that were excluded during the first run. The tour kicked off at The O₂ in London on July 4. The extension took the Sticky & Sweet Tour to a total of over 80 shows, putting it among the top five tours of all time.^[7]

February

• February 1 – At Super Bowl XLIII at Raymond James Stadium in Tampa, Florida, Faith Hill^[8] and Jennifer Hudson^[9] perform at the pregame show (with Hudson singing the National Anthem) and Bruce Springsteen at the halftime show.^[10]
• February 3 – The Fray released their first studio album in four years, The Fray.^[11]
• February 12 — "Crack a Bottle", performed by Eminem, Dr. Dre and 50 Cent, sets a new record for opening week download sales in the United States, at 418,000 copies. The previous record (335,000) was set by "Live Your Life".^[12]
  • Billboard announces that Madonna is the highest-earning entertainer of 2008, with US$242,176,466, mostly from her sold-out Sticky & Sweet Tour.^[13]
• February 8 – The 51st Annual Grammy Awards took place at the Staples Center in Los Angeles. Alison Krauss and Robert Plant took home the most awards with five each, including Album of the Year with their collaborative album, Raising Sand.
  • At the Grammys, Blink-182 announced their reunion and reunion tour after a five-year hiatus.^[14]
  • R&B singer Chris Brown is arrested after he physically assaulted his then girlfriend, Rihanna. He is charged with assault and making criminal threats, and received five years of probation.
• February 13 – Drake releases his third official mixtape So Far Gone, which goes on to become recognized as one of the best modern mixtapes and Drake's launch into mainstream success.^{[citation needed]}
• February 18 – Flo Rida breaks his own record when his single "Right Round" is downloaded 636,000 units in the opening week. His 2008 chart-topper "Low" set the previous record for most downloaded song with 467,000 units sold in the first week of release.^[15]
• February 24 – Lamb of God album Wrath debuts at number 2 on the Billboard 200, making it the highest charting extreme metal album in the last fifteen years.
• February 26 – Vocalist Steven Page leaves the Barenaked Ladies.^[16]

March

• March 3 – Britney Spears launches her world tour at New Orleans Arena in New Orleans, Louisiana. The 97-show tour was her first world tour in five years, and her first tour since her public breakdown.^[17]
• March 5 – Michael Jackson announces his last concert series, This Is It to be held at The O₂ in London. The concerts are never held due to Jackson's death three months later.
• March 6–8 – Phish's reunion shows at Hampton Coliseum in Virginia.
• March 10 – Infernus win the Gorgoroth name dispute.
• March 11 – Tickets go on sale for Michael Jackson's This Is It series, 10 shows extended to 50 shows and impressively all 50 dated sold out in under four hours making them the fastest selling concerts ever in history.
• March 12 – Electroclash singer Miss Kittin reunites with The Hacker to release the duet album Two.
• March 13–22 – The 2009 South by Southwest Conference and Festival.

April

• April 1 – Lady Gaga becomes the first artist since Christina Aguilera in 1999/2000 to reach the top of the Billboard Hot 100 with their first two chart entries ("Just Dance" and "Poker Face").
• April 4 – The 2009 Rock and Roll Hall of Fame induction ceremony takes place, welcoming new inductees Little Anthony & The Imperials, Bobby Womack, Run-D.M.C., and Metallica. Metallica, citing the drama surrounding Blondie, Black Sabbath, and Van Halen's inductions, includes Cliff Burton and Jason Newsted both former bassists for the band in the induction.^[18] Newsted also performs with band in its first rendition as a 5-piece band featuring two bass guitarists.^[19]
• April 5 – The 44th Academy of Country Music Awards took place at the MGM Grand Garden Arena in Las Vegas. Carrie Underwood wins the ACM Entertainer of the Year award, becoming only the seventh female to do so in the history of the ceremony's 44 years.
• April 12 – Carrie Underwood's "I Told You So", from her album Carnival Ride, becomes her tenth straight number one in the country songs chart, making her the only country artist in history to have their first 10 singles reach number one.
• April 17–19 – Coachella 2009
• April 27 – Creed announces their reunion, new album and tour after a five-year break. They break up for a second time in 2013, only to reunite again in July 2023.

May

• May 3 – A concert at Madison Square Garden to celebrate the 90th birthday of Pete Seeger features Bruce Springsteen, Joan Baez, Roger McGuinn, Dave Matthews and Eddie Vedder among others.
• May 12 – Lin-Manuel Miranda and Alex Lacamoire perform a rap about Alexander Hamilton at a White House Evening of Poetry, Music and the Spoken Word in Washington, D.C.; this is the origin of the musical Hamilton.
• May 15 – Eminem released his first studio album in five years, Relapse.
  • Green Day released their first studio album in five years, 21st Century Breakdown.
• May 18 – Rapper Dolla is shot and killed in Beverly Hills, California at the Beverly Center.
• May 19 — Method Man & Redman released their first studio album in ten years, Blackout! 2.^[20]
• May 20 – Kris Allen defeats Adam Lambert to win the eighth season of American Idol. This was long time judge Paula Abdul's last season on the show.

June

• June 1 – The Puerto Rican pop singer Ricky Martin announces he is working on a new studio album and first book.
  • Pearl Jam are first musical guests on The Tonight Show with Conan O'Brien, performing new songs.
• June 2 – Dave Matthews Band released their first studio album in four years, Big Whiskey & the GrooGrux King. It is their first release since the death of saxophonist, LeRoi Moore who died a year earlier.
  • Rancid released their first studio album in six year, Let the Dominoes Fall.^[21]
• June 3 – The Black Eyed Peas released their first studio album in four years, The E.N.D..^[22]
• June 25 - Summerfest begins; the event lasts until July 5.
  • Roughly two weeks before his This Is It series of concerts is scheduled to begin, Michael Jackson dies in his Los Angeles home of an accidental overdose of propofil and benzodiazepines, later discovered to be the result of medical malpractice by his personal physician, Conrad Murray. The American music icon's passing triggers a surge in posthumous sales making him the best selling artist of the year, with 35 million albums sold worldwide in the months following his death.^[23][24]

July

• July 7 – A public memorial event for Michael Jackson is held at the Staples Center. Artists such as Stevie Wonder, Usher, Mariah Carey, Jennifer Hudson, John Mayer, Lionel Richie, and Michael's brother, Jermaine Jackson, perform.
  • Maxwell released his first studio album in eight years, BLACKsummers'night.
• July 10 – August 15 – Rockstar Energy Mayhem Festival, headlined by Marilyn Manson and Slayer
• July 13 – Lady Gaga becomes the first artist to have three songs from a debut album to reach number 1 on the Billboard Hot 100 since Fergie's The Dutchess.
• July 17-21 – Paul McCartney performs three sold-out concerts at Citi Field to open the stadium with opening act, The Script. This is because on August 15, 1965, The Beatles performed the first concert at Shea Stadium and McCartney joined Billy Joel on stage a year ago for the last concert there. Joel joined McCartney again on the first night.
• July 24 – Blink-182 start their reunion tour, Blink-182 in Concert, with Fall Out Boy and Weezer.

August

• August 8 – Meghan Lindsay and Josh Jones of Steel Magnolia won the second season of CMT's Can You Duet. Brandon Green and Jonathan Cox of JB Rocket were named runner-up.
• August 18 – Third Eye Blind released their first studio album in six years, Ursa Major.
• August 21 – Vocalist Jim Lindberg announces his departure from Pennywise.^[25]

September

• September 3 – Michael Jackson is interred at Forest Lawn Memorial Park, Glendale, in a private family ceremony.
• September 8 – Phish released their first studio album in five years, Joy.
• September 13 – The MTV Video Music Awards took place at Radio City Music Hall in New York City. During Taylor Swift's acceptance speech for Best Female Video, Kanye West interrupts on her stage her saying, that Beyoncé had one of the best videos of all time. He was referring to Beyoncé's "Single Ladies (Put a Ring on It)". West was removed from the show.^[26]
• September 15 – Living Colour released their first studio album in six years, The Chair in the Doorway.
• 17 – VH1 Divas returns after a five-year hiatus. It took place the Brooklyn Academy of Music in Brooklyn.
• 29 - Alice in Chains released their first studio album in 14 years, Black Gives Way to Blue.^[27]
• September 30 – Australian star Kylie Minogue kicks off her first-ever US Tour, in Oakland, California.

October

• October 2 – Beyoncé Knowles is named Woman of 2009 by Billboard.
• October 2–4 – Austin City Limits 2009^[28]
• October 6 — KISS released their first studio album in 11 years, Sonic Boom.^[29]
• October 15 – Britney Spears's "3" enters the Billboard Hot 100 at number one, her third number one on Billboard Hot 100 and the first non-American Idol related single to enter the chart at number one since 1999.^[30]
• October 27 – Creed released their first studio album in eight years, Full Circle.
• October 28 – Michael Jackson's This Is It, featuring behind the scenes footage in the days before his death, is released. It enters the chart at No. 1, and becomes the best selling documentary of all time, raising over $250 million.

November

• November 11 – The Country Music Association Awards took place at the Sommet Center in Nashville, Tennessee. Brad Paisley and Carrie Underwood's second year hosting.
• November 12 – Steven Tyler denies he is quitting Aerosmith, despite rumors that the band would be in need of a new lead singer.^[31]
• November 22 – The American Music Awards took place at the Microsoft Theater in Los Angeles.

December

• December 8 – Thirty Seconds to Mars released their first studio album Im four years, This Is War.
• December 11 – Garth Brooks comes out of retirement for a solo acoustic show at the Encore Theater at Wynn Las Vegas.^[32]
• December 16 – John Frusciante announces his second departure from the Red Hot Chili Peppers.

January

February

March

April

May

June

July

August

September

October

November

December

Billboard Hot 100 No. 1 Songs

• "3" – Britney Spears (1 week)
• "Boom Boom Pow" – The Black Eyed Peas (12 weeks)
• "Crack a Bottle" – Eminem featuring Dr. Dre and 50 Cent (1 week)
• "Down" – Jay Sean featuring Lil Wayne (2 weeks)
• "Empire State of Mind" – Jay-Z featuring Alicia Keys (5 weeks)
• "Fireflies" – Owl City (2 weeks)
• "I Gotta Feeling" – The Black Eyed Peas (14 weeks)
• "Just Dance" – Lady Gaga featuring Colby O'Donis (3 weeks)
• "My Life Would Suck Without You" – Kelly Clarkson (2 weeks)
• "Poker Face" – Lady Gaga (1 week)
• "Right Round" – Flo Rida featuring Ke$ha (6 weeks)
• "Single Ladies (Put a Ring on It)" – Beyoncé (2 weeks in 2008, 2 weeks in 2009)
• "Whatcha Say" – Jason Derülo (1 week)

Billboard Hot 100 Top 20 Hits

Billboard Year-End Hot 100 singles of 2009