Question: The Robbie Williams album "Live at Knebworth" is a compilation of songs performed during shows at a festival that began in what year?

full_context: Document 1: Live at Wembley (Beyoncé album): Live at Wembley is a live album by American singer Beyoncé. It was released on April 26, 2004 through Columbia Music Video and Sony Music Entertainment. The DVD features her concert at Wembley Arena in London, England, as part of her Dangerously in Love Tour in support of her debut solo studio album "Dangerously in Love" (2003). Most of the songs on "Live at Wembley" originate from "Dangerously in Love", although Beyoncé also performed a medley of past songs by her former group Destiny's Child. "Live at Wembley" was critically acclaimed, with AllMusic giving it a grade of three-and-a-half stars out of five. The cover of Rose Royce's "Wishing on a Star", included on the album, was nominated in the category for Best Female R&B Vocal Performance at the 48th Annual Grammy Awards (2006).
Document 2: Abbey Road on the River: Abbey Road on the River (AROTR) is a five-day, multi-staged music festival which was initially created to honor the music and spirit of The Beatles. The festival took place in Louisville, Kentucky over Memorial Day weekend but moved across the river to Jeffersonville, Indiana starting in 2017. Tribute bands, as well as internationally recognized bands, perform over the course of the festival, playing the music of The Beatles, as well as the music of other artists. Abbey Road on the River is a four-time winner of the Kentucky Travel Industry Association's Top 10 Spring Festivals.
Document 3: Tír na nÓg concerts: From 1970 through 1975, then from 1985 through present, Irish folk group Tír na nÓg especially performed concerts in the United Kingdom, either as a support act to bands and solo artists like Jethro Tull, Steeleye Span, Supertramp, Elton John, Hawkwind or as main performers.
Document 4: Live at Knebworth: Live at Knebworth, also known as Live Summer 2003 with different cover text, is a live album by English pop singer Robbie Williams, recorded and released in 2003. The album is his first live album, and is a compilation of songs performed during three consecutive shows at Knebworth, England on 1–3 August 2003.
Document 5: Woodstock: The Woodstock Music & Art Fair—informally, the Woodstock Festival or simply Woodstock— was a music festival in the United States in 1969 which attracted an audience of over 400,000. Scheduled for August 15–17 on a dairy farm in the Catskill Mountains of southern New York, northwest of New York City, it ran over to Monday,
Document 6: Concerts at Knebworth House: The Knebworth Festival is a recurring open air rock and pop concert held on the grounds of the Knebworth House in Knebworth, England. The festival first occurred in 1974 when The Allman Brothers Band, The Doobie Brothers and other artists attracted 60,000 people.
Document 7: California Jam: California Jam (also known as Cal Jam) was a rock music festival co-headlined by Deep Purple and Emerson, Lake & Palmer, held at the Ontario Motor Speedway in Ontario, California, on April 6, 1974. It was produced by ABC Entertainment, Sandy Feldman and Leonard Stogel. Pacific Presentations, a Los Angeles-based concert company headed by Sepp Donahower and Gary Perkins, coordinated the event, booked all the talent and ran the advertising. Don Branker worked for Leonard Stogel and was responsible for concert site facilitation, toilets, fencing and medical. It attracted 300,000-400,000 paying fans. The festival set what were then records for the loudest amplification system ever installed, the highest paid attendance, and highest gross in history. It was the last of the original wave of rock festivals, as well as one of the most well-executed and financially successful, and presaged the era of media consolidation and the corporatization of the rock music industry.
Document 8: Justin Timberlake: Live from London: Justin Timberlake: Live from London is the first live video album by American singer-songwriter Justin Timberlake. It was released on December 15, 2003, by Jive Records. It documents Timberlake's performance at the London Arena on May 18, 2003.
Document 9: What We Did Last Summer: What We Did Last Summer – Robbie Williams: Live at Knebworth is a live DVD by Robbie Williams, recorded between 1–3 August 2003 at Knebworth, England as part of the Weekends of Mass Distraction Tour, the second last venue on the first leg of the tour.
Document 10: Robbie Williams: Live at the O2: Robbie Williams: Live at the O2 is a live album released by British singer-songwriter Robbie Williams on 24 November 2012, as a commemoration of his live performances at The O2, London on 22, 23 and 24 November 2012. The album was available to attendants of the concerts straight after the performances, and later via Williams' official website. The album features guest appearances from Gary Barlow and Guy Chambers. The album contains three discs, each of which contains part of the specific concert in question.
Document 11: The Robbie Williams Show: The Robbie Williams Show is a live DVD and VHS video by Robbie Williams, recorded in 2002 in Pinewood Studios before the release of the album "Escapology". Many of the album's songs were performed for the first time here, with Robbie jokingly declaring to some fans that they may have already heard some of the new songs (such as "Something Beautiful"), but only through unauthorized Internet leaks.
Document 12: Mann Center for the Performing Arts: The Mann Center for the Performing Arts (formerly known as the Mann Music Center) is a nonprofit performing arts center located in the Centennial District of Philadelphia's West Fairmount Park, built in 1976 as the summer home for the Philadelphia Orchestra. It is the successor in this role to the Robin Hood Dell, where the Philadelphians have given summer performances since 1935. It has since hosted numerous world-class artists and touring companies such as the American Ballet Theatre with Mikhail Baryshnikov, Marian Anderson, Leonard Bernstein, Buena Vista Social Club, Ray Charles, Judy Garland, the Metropolitan Opera, Mormon Tabernacle Choir, Paul Robeson, Itzhak Perlman, Lang Lang, Midori, and Yo-Yo Ma. Major Philadelphia premieres have included the Israel Philharmonic Orchestra, Bolshoi Ballet and Orchestra’s production of Spartacus, and Britain’s Royal Ballet’s productions of Romeo and Juliet and Swan Lake. Among the scores of award-winning popular artists presented by the Mann in recent years are Jack Johnson, Ed Sheeran, Phish, Tony Bennett, Mary J. Blige, Roger Daltrey, Bob Dylan, Furthur, Arcade Fire, Aretha Franklin, Herbie Hancock, Norah Jones, Diana Krall, Wynton Marsalis, Willie Nelson, Smokey Robinson, Jill Scott, James Taylor, Damien Rice, Alabama Shakes, Bon Iver, Lana Del Rey, The National, and Stevie Ray Vaughan. In 2010, 2011 & 2014, the Mann was nominated by Pollstar, a concert industry trade publication, as "Best Major Outdoor Concert Venue" in North America. The venue has a total seating capacity of approximately 14,000, with 4,743 seats under the roof and over 8,600 outside.
Document 13: Winger Live: Winger Live is a two CD and DVD live set culled from Winger 2007 US reunion tour and directed by Jack Edward Sawyers. Kip Winger, Reb Beach, Rod Morgenstein and John Roth rip through all the hits, progressive jams and new material taken from their comeback album IV. Keyboardist Cenk Eroglu was not present for this show, despite his appearance on IV. The concert was recorded live straight through with no interruptions at the Galaxy Concert Theater in Santa Ana, California. The cover consists of a checkerboard-style grid of live still frames pulled from the video footage itself.
Document 14: Live at Wembley (Bring Me the Horizon album): Live at Wembley is a live album by British rock band Bring Me the Horizon. It was recorded live on 5 December 2014 during the headline show at Wembley Arena in Wembley, London. The opening acts included Young Guns, Issues as well as Sleepwave. The live album was released on 22 June 2015 with very few copies made, and selling out very quickly. This was the first time the band had played the song "Pray for Plagues" in over three years, and was played alongside ex-rhythm guitarist, Curtis Ward, whom they had not performed with since his departure in 2009.
Document 15: Live at the Albert: ""Robbie Williams: Live at the Albert"" is a DVD that was released in December 2001 of the show performed on 10 October 2001; concert that Robbie Williams gave at Royal Albert Hall a month before the release of the album Swing When You're Winning. It has since been certified 6x Platinum in the United Kingdom and 2x Platinum in Germany.
ground_truth: 1974