Question: Who founded the famous chain of music-themed restaurants which opened its first establishment in the city Chopin went to in the spring of 1848?

full_context: Document 1: Hard Rock Cafe: The chain began to expand worldwide in 1982 with locations in (among others) Toronto, Los Angeles, San Francisco, Chicago, Paris, and Berlin. Hard Rock Cafe locations in the United States vary from smaller, more tourist driven markets (Biloxi, Pigeon Forge, Key West, etc.) to large metropolises (Houston, Philadelphia, New York City, Chicago, Boston, Washington, D.C., etc.). Hard Rock Cafe typically does not franchise cafe locations in the United States. All US cafes are corporate owned and operated, except for cafes in Tampa and Four Winds New Buffalo casino. However, in the transition of the Las Vegas Hard Rock Hotel property originally owned and then later sold to Rank by founder Peter Morton, Morton retained hotel naming rights west of the Mississippi. When Morton sold his Las Vegas Hard Rock Hotel to the Morgans Hotel Group, he also sold those naming rights, which then gave rise to two US franchised hotels (without cafes) in Albuquerque and Tulsa. The Albuquerque hotel no longer pays for the Hard Rock rights and reverted to its former name in June 2013. More hotels franchised from Morgan's are planned for Sioux City and Vancouver.
Document 2: London: London was instrumental in the development of punk music, with figures such as the Sex Pistols, The Clash, and Vivienne Westwood all based in the city. More recent artists to emerge from the London music scene include George Michael, Kate Bush, Seal, Siouxsie and the Banshees, Bush, the Spice Girls, Jamiroquai, Blur, The Prodigy, Gorillaz, Mumford & Sons, Coldplay, Amy Winehouse, Adele, Ed Sheeran and One Direction. London is also a centre for urban music. In particular the genres UK garage, drum and bass, dubstep and grime evolved in the city from the foreign genres of hip hop and reggae, alongside local drum and bass. Black music station BBC Radio 1Xtra was set up to support the rise of home-grown urban music both in London and in the rest of the UK.
Document 3: Mexico City: The city is also a leading center of popular culture and music. There are a multitude of venues hosting Spanish and foreign-language performers. These include the 10,000-seat National Auditorium that regularly schedules the Spanish and English-language pop and rock artists, as well as many of the world's leading performing arts ensembles, the auditorium also broadcasts Grand Opera performances from New York's Metropolitan Opera on giant, high definition screens. In 2007 National Auditorium was selected world's best venue by multiple genre media.
Document 4: Frédéric Chopin: With his health further deteriorating, Chopin desired to have a family member with him. In June 1849 his sister Ludwika came to Paris with her husband and daughter, and in September, supported by a loan from Jane Stirling, he took an apartment at Place Vendôme 12. After 15 October, when his condition took a marked turn for the worse, only a handful of his closest friends remained with him, although Viardot remarked sardonically that "all the grand Parisian ladies considered it de rigueur to faint in his room."
Document 5: Hard Rock Hotel & Casino Atlantic City: Construction of what was originally known as the Taj Mahal commenced in 1983 by Resorts International, owner of the neighboring Resorts Casino Hotel, with an estimated budget of $250 million. Resorts head James Crosby said it might be named the United States Hotel, in reference to the city's first major hotel.
Document 6: Frédéric Chopin: At the age of 21 he settled in Paris. Thereafter, during the last 18 years of his life, he gave only some 30 public performances, preferring the more intimate atmosphere of the salon. He supported himself by selling his compositions and teaching piano, for which he was in high demand. Chopin formed a friendship with Franz Liszt and was admired by many of his musical contemporaries, including Robert Schumann. In 1835 he obtained French citizenship. After a failed engagement to Maria Wodzińska, from 1837 to 1847 he maintained an often troubled relationship with the French writer George Sand. A brief and unhappy visit to Majorca with Sand in 1838–39 was one of his most productive periods of composition. In his last years, he was financially supported by his admirer Jane Stirling, who also arranged for him to visit Scotland in 1848. Through most of his life, Chopin suffered from poor health. He died in Paris in 1849, probably of tuberculosis.
Document 7: Hard Rock Cafe: In 1990, The Rank Group, a London-based leisure company, acquired Mecca Leisure Group and continued expansion of the concept in its geographic territory. Rank went on to purchase Hard Rock America from Peter Morton as well as Hard Rock Canada from Nick Bitove. After the completion of these acquisitions, Rank gained worldwide control of the brand. In March 2007, the Seminole Tribe of Florida acquired Hard Rock Cafe International, Inc. and other related entities from Rank for US$965 million.In 2008, anonymous members of the wait staff criticized the business because of its practice of paying them less than half the official minimum wage in the UK, with the business allocating tips to staff to bring their salaries within the law. Most customers, it was argued, do not realize that they are subsidizing a low wage when they give the tip.
Document 8: Isaac Tigrett: Isaac Burton Tigrett (born November 28, 1948, Jackson, Tennessee) is an American businessman, best known as the co-founder of Hard Rock Café and House of Blues.
Document 9: Frédéric Chopin: In April, during the Revolution of 1848 in Paris, he left for London, where he performed at several concerts and at numerous receptions in great houses. This tour was suggested to him by his Scottish pupil Jane Stirling and her elder sister. Stirling also made all the logistical arrangements and provided much of the necessary funding.
Document 10: Isaac Tigrett: On June 14, 1971 he and Peter Morton started the first Hard Rock Café (HRC) restaurant in London's fashionable Mayfair district. The restaurant combined rock music, memorabilia related to rock 'n' roll and American cuisine.
Document 11: London: London has numerous venues for rock and pop concerts, including the world's busiest arena the o2 arena and other large arenas such as Earls Court, Wembley Arena, as well as many mid-sized venues, such as Brixton Academy, the Hammersmith Apollo and the Shepherd's Bush Empire. Several music festivals, including the Wireless Festival, South West Four, Lovebox, and Hyde Park's British Summer Time are all held in London. The city is home to the first and original Hard Rock Cafe and the Abbey Road Studios where The Beatles recorded many of their hits. In the 1960s, 1970s and 1980s, musicians and groups like Elton John, Pink Floyd, David Bowie, Queen, The Kinks, The Rolling Stones, The Who, Eric Clapton, Led Zeppelin, The Small Faces, Iron Maiden, Fleetwood Mac, Elvis Costello, Cat Stevens, The Police, The Cure, Madness, The Jam, Dusty Springfield, Phil Collins, Rod Stewart and Sade, derived their sound from the streets and rhythms vibrating through London.
Document 12: Southampton: Southampton has two large live music venues, the Mayflower Theatre (formerly the Gaumont Theatre) and the Guildhall. The Guildhall has seen concerts from a wide range of popular artists including Pink Floyd, David Bowie, Delirious?, Manic Street Preachers, The Killers, The Kaiser Chiefs, Amy Winehouse, Lostprophets, The Midnight Beast, Modestep, and All Time Low. It also hosts classical concerts presented by the Bournemouth Symphony Orchestra, City of Southampton Orchestra, Southampton Concert Orchestra, Southampton Philharmonic Choir and Southampton Choral Society.
Document 13: Frédéric Chopin: In late summer he was invited by Jane Stirling to visit Scotland, where he stayed at Calder House near Edinburgh and at Johnstone Castle in Renfrewshire, both owned by members of Stirling's family. She clearly had a notion of going beyond mere friendship, and Chopin was obliged to make it clear to her that this could not be so. He wrote at this time to Grzymała "My Scottish ladies are kind, but such bores", and responding to a rumour about his involvement, answered that he was "closer to the grave than the nuptial bed." He gave a public concert in Glasgow on 27 September, and another in Edinburgh, at the Hopetoun Rooms on Queen Street (now Erskine House) on 4 October. In late October 1848, while staying at 10 Warriston Crescent in Edinburgh with the Polish physician Adam Łyszczyński, he wrote out his last will and testament—"a kind of disposition to be made of my stuff in the future, if I should drop dead somewhere", he wrote to Grzymała.
Document 14: Frédéric Chopin: Two Polish friends in Paris were also to play important roles in Chopin's life there. His fellow student at the Warsaw Conservatory, Julian Fontana, had originally tried unsuccessfully to establish himself in England; Albert Grzymała, who in Paris became a wealthy financier and society figure, often acted as Chopin's adviser and "gradually began to fill the role of elder brother in [his] life." Fontana was to become, in the words of Michałowski and Samson, Chopin's "general factotum and copyist".
Document 15: Mexico City: Other popular sites for pop-artist performances include the 3,000-seat Teatro Metropolitan, the 15,000-seat Palacio de los Deportes, and the larger 50,000-seat Foro Sol Stadium, where popular international artists perform on a regular basis. The Cirque du Soleil has held several seasons at the Carpa Santa Fe, in the Santa Fe district in the western part of the city. There are numerous venues for smaller musical ensembles and solo performers. These include the Hard Rock Live, Bataclán, Foro Scotiabank, Lunario, Circo Volador and Voilá Acoustique. Recent additions include the 20,000-seat Arena Ciudad de México, the 3,000-seat Pepsi Center World Trade Center, and the 2,500-seat Auditorio Blackberry.
ground_truth: Peter Morton
sub_queries: Where did Chopin go in the spring of 1848? Answer: London
What famous chain of music-themed restaurants opened its first establishment in London ? Answer: Hard Rock Cafe
Hard Rock Cafe >> founded by Answer: Peter Morton