In the 1970s Led Zeppelin reached new heights of commercial and critical success that made them one of the most influential groups of the era, dwarfing their earlier achievements. The band's image also changed as the members began to wear elaborate, flamboyant clothing. Led Zeppelin began travelling in a private jet airliner, a Boeing 720, (nicknamed the Starship), rented out entire sections of hotels (including the Continental Hyatt House in Los Angeles, known colloquially as the "Riot House"), and became the subject of frequently repeated stories of debauchery. One involved John Bonham riding a motorcycle through a rented floor of the Riot House, while another involved the destruction of a room in the Tokyo Hilton, leading to the group being banned from that establishment for life. Although Led Zeppelin developed a reputation for trashing their hotel suites and throwing television sets out of the windows, some suggest that these tales have been exaggerated. Music journalist Chris Welch argues that "[Led Zeppelin's] travels spawned many stories, but it was a myth that were constantly engaged in acts of wanton destruction and lewd behaviour". A black and white photograph of Robert Plant with a tambourine and Jimmy Page with an acoustic guitar seated and performing Plant and Page perform acoustically in Hamburg in March 1973, just before the release of the band's fifth album, Houses of the Holy Led Zeppelin released their fourth album on 8 November 1971. In response to the treatment the band had received from critics, particularly after Led Zeppelin III, the band decided to release the fourth album with no title, though it is variously referred to as Led Zeppelin IV, Untitled, IV, or, due to the four symbols appearing on the record label, as Four Symbols, Zoso or Runes. In addition to lacking a title, the original cover featured no band name, as the group wished to be anonymous and to avoid easy pigeonholing by the press. With 37 million copies sold, Led Zeppelin IV is one of the best-selling albums in history, and its massive popularity cemented Led Zeppelin's status as superstars in the 1970s. By 2006, it had sold 23 million copies in the United States alone. The track "Stairway to Heaven", never released as a single, is sometimes quoted as being the most requested and most played album-orientated rock (AOR) FM radio song. The group followed up the album's release with tours of the UK, Australasia, North America, Japan, and the UK again from late 1971 through early 1973. Led Zeppelin's next album, Houses of the Holy, was released in March 1973. It featured further experimentation by the band, who expanded their use of synthesisers and mellotron orchestration. The predominately orange album cover, designed by the London-based design group Hipgnosis, depicts images of nude children climbing the Giant's Causeway in Northern Ireland. Although the children are not shown from the front, the cover was controversial at the time of the album's release. As with the band's fourth album, neither their name nor the album title was printed on the sleeve. Houses of the Holy topped charts worldwide, and the band's subsequent concert tour of North America in 1973 broke records for attendance, as they consistently filled large auditoriums and stadiums. At Tampa Stadium in Florida, they played to 56,800 fans, breaking the record set by the Beatles' 1965 Shea Stadium concert and grossing $309,000. Three sold-out shows at Madison Square Garden in New York City were filmed for a motion picture, but the theatrical release of this project (The Song Remains the Same) was delayed until 1976. Before the final night's performance, $180,000 of the band's money from gate receipts was stolen from a safe deposit box at the Drake Hotel. A colour photograph of the four members of Led Zeppelin performing onstage, with some other figures visible in the background Led Zeppelin perform at Chicago Stadium in January 1975, a few weeks before the release of Physical Graffiti In 1974, Led Zeppelin took a break from touring and launched their own record label, Swan Song, named after an unreleased song. The record label's logo, based on a drawing called Evening: Fall of Day (1869) by William Rimmer, features a picture of Apollo. The logo can be found on Led Zeppelin memorabilia, especially t-shirts. In addition to using Swan Song as a vehicle to promote their own albums, the band expanded the label's roster, signing artists such as Bad Company, the Pretty Things and Maggie Bell. The label was successful while Led Zeppelin existed, but folded less than three years after they disbanded. In 1975, Led Zeppelin's double album Physical Graffiti was their first release on the Swan Song label. It consisted of fifteen songs, of which eight had been recorded at Headley Grange in 1974 and seven had been recorded earlier. A review in Rolling Stone magazine referred to Physical Graffiti as Led Zeppelin's "bid for artistic respectability", adding that the only bands Led Zeppelin had to compete with for the title "The World's Best Rock Band" were the Rolling Stones and the Who. The album was a massive fiscal and critical success. Shortly after the release of Physical Graffiti, all previous Led Zeppelin albums simultaneously re-entered the top-200 album chart, and the band embarked on another North American tour, now employing sophisticated sound and lighting systems. In May 1975, Led Zeppelin played five sold-out nights at the Earls Court Arena in London, at the time the largest arena in Britain.