Question: Who is the mother of the person who performed Live at Rockpalast?

full_context: Document 1: Ed Sheeran: Sheeran was born in Halifax, West Yorkshire on 17 February 1991. When he was a child, he moved with his family from Hebden Bridge to Framlingham in Suffolk. He has an older brother named Matthew who works as a composer. Sheeran's parents, John and Imogen, are from London. His paternal grandparents are Irish, and Sheeran has stated that his father is from a "very large" Catholic family. John is an art curator and lecturer, and Imogen is a culture publicist turned jewellery designer. His parents ran Sheeran Lock, an independent art consultancy, from 1990 to 2010.Sheeran sang in a local church choir from the age of four, learned to play the guitar during his time at Rishworth School, and began writing songs while at Thomas Mills High School in Framlingham. He was accepted at the National Youth Theatre in London as a teenager. He successfully auditioned for Youth Music Theatre UK in 2007 and joined their production of Frankenstein in Plymouth. He is a patron of Youth Music Theatre UK (now renamed British Youth Music Theatre) and of Access to Music, where he studied Artist Development. Sheeran is a second cousin of Northern Irish broadcaster Gordon Burns, who hosted the British game show The Krypton Factor.
Document 2: John Cale: John Davies Cale was born on 9 March 1942 in Garnant in the industrial Amman Valley of Wales to Will Cale, a coal miner, and Margaret Davies, a primary school teacher. Although his father spoke only English, his mother spoke and taught Welsh to Cale, which hindered his relationship with his father, although he began learning English at primary school, at around the age of seven. Cale was molested by two different men during his youth, an Anglican priest who molested him in a church and a music teacher.
Document 3: Living with You: "Living with You" is a song by Welsh musician and composer John Cale. It was released as a digital single on 25 February 2013. It was the third single from Cale's new album "Shifty Adventures in Nookie Wood". Music and lyrics was written by Cale himself. As B-side of this single are "Living with You (Organic Mix)" and "Living with You (Laurel Halo remix)".
Document 4: Hywel Teifi Edwards: Born and raised in Aberarth, Ceredigion, Edwards attended Aberaeron Grammar School and the University College of Wales, Aberystwyth. He taught Welsh at Garw Grammar School, Pontycymmer, where he met his wife Aerona, before becoming an extramural lecturer in Welsh literature at University of Wales, Swansea, and later Professor and Head of the Welsh Department. He and his wife had two children, Huw Edwards and Meinir Edwards now Menir Krishnasamy. He retired from full-time teaching in 1995 but continued to lecture and write books. Edwards was the leading authority on the history of the National Eisteddfod of Wales.
Document 5: Roger Waters: Waters was born on 6 September 1943, the younger of two boys, to Mary (née Whyte; 1913–2009) and Eric Fletcher Waters (1914–1944), in Great Bookham, Surrey. His father, the son of a coal miner and Labour Party activist, was a schoolteacher, a devout Christian, and a Communist Party member. In the early years of the Second World War, Waters' father was a conscientious objector who drove an ambulance during the Blitz.
Document 6: Live at Leeds: Live at Leeds is the first live album by the English rock band The Who. It was recorded at the University Refectory, University of Leeds on 14 February 1970, and is the only live album that was released while the group were still actively recording and performing with their best known line - up of Roger Daltrey, Pete Townshend, John Entwistle and Keith Moon. Initially released in the United States on 16 May, by Decca and MCA and the United Kingdom on 23 May, by Track and Polydor, the album has been reissued on several occasions and in several different formats. Since its release, Live at Leeds has been cited by several music critics as the best live rock recording of all time.
Document 7: Process (John Cale album): Process is the soundtrack album by Welsh multi-instrumentalist and composer John Cale. It was released in August 2005 on French independent label Syntax Records. It was produced, composed and performed by John Cale. It is the original music score for C.S. Leigh's film "Process". It was primarily released on CD and three tracks from album ("Suicide Theme", "Candles" and "Reading Poem") was also released on limited 10" vinyl album.
Document 8: Circus Live: Circus Live is a 3-disc live album by John Cale released on February 19, 2007. The contents were recorded live on the 2004 and 2006 European tours. One of the discs is a DVD containing rehearsal footage, a music video, and a two audio tracks.
Document 9: Live at Rockpalast (John Cale album): Live at Rockpalast is a two-disc live album by Welsh musician John Cale. It was released in October 2010 on German record label Made in Germany. It was recorded during his two shows for German music television show Rockpalast on 14 October 1984 at Grugahalle, Essen (first disc; with full band) and 6 March 1983 at Zeche, Bochum (second disc; Cale solo with guitar and piano). This concert is missing "Risé, Sam And Rimsky-Korsakov" (Cale, Shepard) narrated by his then-wife Risé Irushalmi.
Document 10: Live: The Loreley Tapes: Live: The Loreley Tapes... is a live album by Paul Rodgers of Free and Bad Company fame. It was recorded at the Rockpalast Open Air Festival, at Loreley, Germany on 8 July 1995 and released in 1996.
Document 11: Kenton Cool: Cool was born in Slough, Berkshire in 1973. His family surname was originally Kuhle and was changed during the Second World War by his half-German grandfather. His father was a photographer and his mother a florist, and the family home was near to Uxbridge, in Middlesex. He was schooled at John Hampden Grammar School in High Wycombe, and later obtained a place at the University of Leeds. Kenton Cool graduated from the University of Leeds in 1994 after studying BSc Geological Sciences.
Document 12: Bramwell Booth: Born in Halifax, Yorkshire, England, the oldest child born to William Booth and Catherine Mumford, he had two brothers and five sisters, including Evangeline Booth, Catherine Booth-Clibborn, Emma Booth and Ballington Booth. The Booth family regularly moved from place to place as William Booth's ministry necessitated until the family finally settled in London in 1865. Bramwell Booth was involved in The Salvation Army right from its origins as the obscure Christian Mission, established in Whitechapel in 1865, into an international organisation with numerous and varied social activities. He was educated at home, briefly at a preparatory school and at the City of London School, where he was bullied.
Document 13: Idwal Robling: Robling was born in Ynyshir in the Rhondda Valley, where he attended the local grammar school. His education was interrupted by the Second World War, and upon being called up was accepted for service in the Royal Navy. However, he was selected by ballot to become a Bevin Boy so instead of going to the Navy he was conscripted to work in the coal mines. After the war, he resumed his education and qualified as a teacher after attending Caerleon College and Loughborough University, although instead of teaching he decided on a different career and became a manager at the Lovell's sweet factory in Newport, Monmouthshire.
Document 14: Fragments of a Rainy Season: Fragments of a Rainy Season is a 1992 live solo album by John Cale, performed at various locations during his 1992 tour. A 16-track DVD, recorded at the Centre for Fine Arts, Brussels (Palais des Beaux-Arts, now BOZAR) in Brussels, Belgium, that features the tracks in the order in which they were performed, was also released. The album cover was designed by noted conceptual artist Joseph Kosuth.
Document 15: Gwynfor Evans: Gwynfor Evans was born in Barry, near Cardiff, to Dan Evans and Catherine Richard. He had a brother named Alcwyn, and a sister named Ceridwen. His father ran a chain of shops in Barry, and his mother a china shop. His mother was a fluent Welsh speaker. As a boy, he was educated at Gladstone Road School. Later on he was educated at Barry County School, where he was captain of the school's cricket and hockey teams. At the school he began learning the Welsh language, but did not become fully fluent until the age of seventeen.
ground_truth: Margaret Davies
sub_queries: Live at Rockpalast >> performer Answer: John Cale
Who is the mother of John Cale ? Answer: Margaret Davies