Question: Who is the mother of the performer of All Summer Long?

full_context: Document 1: 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 2: All Summer Long (John Cale song): "All Summer Long" is a song by Welsh musician and composer John Cale. It was released as a digital single in August 2013, while on the B-side was the song "Sandman (Flying Dutchman)" from Cale's album "Shifty Adventures in Nookie Wood" from the previous year. "All Summer Long" was released only on this single, but not on any studio album. It was recorded during the recording sessions for "Shifty Adventures in Nookie Wood".
Document 3: 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 4: Extra Playful: Extra Playful is a 2011 EP by John Cale. The EP features 5 previously unreleased songs. Black Edition (released on Black Friday) contains two more extra songs.
Document 5: If You Were Still Around: "If You Were Still Around" is a song by Welsh musician and composer John Cale. It was written by John Cale together with playwright Sam Shepard. It was originally released on Cale's 1982 album "Music for a New Society". On 27 October 2014, a year after the death of his The Velvet Underground–bandmate Lou Reed, Cale released a new version of this song. For this version was also released music video directed by Abigail Portner. At the beginning of the video Cale is lying on the floor in a fetal position and after he views the photos of Reed and other deceased people associated with the Velvet Underground and The Factory: Sterling Morrison, Nico, Andy Warhol, and Edie Sedgwick.
Document 6: 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 7: Dance Music (album): Dance Music is the soundtrack album by Welsh multi-instrumentalist and composer John Cale. It was released in 1998 on Detour Records label. It was produced by Cale and his then collaborator Jean-Michel Reusser. It is original music score for Ed Wubbe's ballet about Cale's long-time collaborator Nico. Most of the songs was performed by Dutch group Ice Nine (except "Ari Sleepy Too" and "Nibelungen" by Nico and "España" by Cale on piano).
Document 8: Seducing Down the Door: Seducing Down the Door: A Collection 1970−1990 is the second compilation album by Welsh musician John Cale, released by Rhino Records in July 1994. It featured songs from Cale's albums released between 1970 and 1990 (including songs from collaborative albums with Brian Eno and Lou Reed). It includes the songs "Jack the Ripper", an unreleased single from 1978, and "Temper", an outtake from "The Academy in Peril" album.
Document 9: Face to the Sky: "Face to the Sky" is a song by Welsh musician and composer John Cale. It was released as a digital single on 29 August 2012 and as 7" vinyl record on 25 September 2012. It was the second 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 is "Living with You (Organic Mix)". Video for this song, directed by Tom Scholefield (a.k.a. Kon Om Pax), was premiered at "Stereogum".
Document 10: 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 11: 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 12: 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 13: 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 14: 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.
Document 15: 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.
ground_truth: Margaret Davies
sub_queries: All Summer Long >> performer Answer: John Cale
Who is the mother of John Cale ? Answer: Margaret Davies