Question: What is the nationality of the singer-songwriter who was president of the Aeolian Singers?
Context: A Turkish Air Force F-16 fighter jet shot down a Russian Sukhoi Su-24M attack aircraft near the Syria–Turkey border on 24 November 2015.  According to Turkey, the aircraft—whose nationality was unknown at the time—was fired upon while in Turkish airspace because it violated the border up to a depth of 1.36 mi for about 17 seconds after being warned to change its heading 10 times over a period of five minutes before entering the airspace.  The Russia Defence Ministry denied the aircraft ever left Syrian airspace, counter-claiming that their satellite data showed that the Sukhoi was about 1000 m inside Syrian airspace when it was shot down.  The US State Department said that the US independently confirmed that the aircraft's flight path violated Turkish territory, and that the Turks gave multiple warnings to the pilot, to which they received no response and released audio recordings of the warnings they had broadcast.  Turkish President Recep Tayyip Erdogan pointed out that Turkey had the right to defend its airspace.  Russian president Vladimir Putin said that the US knew the flight path of the Russian jet and should have informed Turkey; two US officials said that Russia did not inform the US military of its jet's flight plan. Cornelio Sommaruga (born December 29, 1932 in Rome) is a prominent Swiss humanitarian, lawyer and diplomat who is best known for being President of the International Committee of the Red Cross (ICRC) from 1987 to 1999.  Today, he chairs the Geneva International Centre for Humanitarian Demining (GICHD) in Geneva.  He is also active on a number of boards, such as the International Union Against Cancer.  Currently he is Chair of the Board of Directors of the Foundation For the Future, an organization dedicated to promoting human rights in the Middle East and North Africa, and the honorary President of Initiatives of Change International, a global organization dedicated to "building trust across the world's divides" of culture, nationality, belief, and background. Sebastian Forbes (born 22 May 1941) is a musical composer, conductor, founder of the Aeolian Singers and professor of music at the University of Surrey.  He comes from a musical family (his father being the Scottish violist, Watson Forbes) and he was taught by Martindale Sidwell. Peter Skellern (14 March 1947 – 17 February 2017) was an English singer-songwriter and pianist.  The use of brass bands and choirs in his music to create a nostalgic and romantic feel became his trademark.  In October 2016, he was ordained as a deacon and priest of the Church of England, but died only four months later from a brain tumour. The Bidu Sayão International Vocal Competition (Portuguese: Concurso Internacional de Canto Bidu Sayão) is a singing competition held at the city of Belo Horizonte in Brazil named after that country's most famous opera singer, Bidu Sayão.  It is a competition open to singers of any nationality for up-and-coming young singers and as such has an age restriction.  The competition is divided between male and female participants and is the most important vocal competition in Latin America. Ahmad Tibi (Arabic: أحمد الطيبي‎ ‎ , ] , Hebrew: אחמד טיבי‎ ‎ , sometimes spelled Ahmed Tibi; born 19 December 1958) is an Arab-Muslim Israeli politician and leader of the Arab Movement for Change (Ta'al), an Arab party in Israel.  He has served as a member of the Knesset (the Israeli Parliament) since 1999, and currently serves as one of ten Deputy Speakers of the Knesset, representing the Arab Israeli MK block.  Tibi was acknowledged as a figure in the Israeli-Palestinian arena after serving as a political advisor to the late Palestinian president Yasser Arafat (1993–1999).  He describes himself as Arab-Palestinian in nationality, and Israeli in citizenship. Executive Order 12172 was issued by American president Jimmy Carter on November 26, 1979, shortly after the Iran hostage crisis had started.  This Executive Order invoked the Immigration and Nationality Act of 1952 and called for the Secretary of State and the Attorney General to exercise in respect of Iranians holding nonimmigrant visas, the authority conferred upon the President by section 215(a) (1) of the Act of June 27, 1952 (8 USC 1185), to prescribe limitations and exceptions on the rules and regulations governing the entry of aliens into the United States. The Aeolian Singers, president Peter Skellern, musical director Stephen Jones, rehearsal pianist Anna Le Hair, was established in 1963.  With about 80 members, it is Hemel Hempstead's largest mixed-voice chorus.  While based in Hertfordshire, the singers also perform in major London concert halls and in other parts of Europe.  In recent years they have performed in Ghent, Paris and Provence and visited Mannheim in October 2006, where they performed in two concerts together with the Konzertchor der Stadt Mannheim.  They have a very wide repertoire ranging from Renaissance to contemporary music, and have given several first performances.  They also have a tradition of community and youth involvement. Giovanni Vincenzo "Gianni" Infantino (] ; born 23 March 1970) is a football administrator and current FIFA president.  He holds dual nationality, Swiss and Italian.  He has been the general secretary of UEFA since 2009 and was elected president of FIFA during the 2016 FIFA Extraordinary Congress on 26 February 2016. The Order of Fidelity (Urdhëri Besa), also known as Order of Besa, was founded by King Zog I when he was President of Albania.  Founded on 22 December 1926, it was initially awarded in four classes (1.  Grand Cordon with star-Kordon i Madh me Yll 2.  Grand Officer-Oficer i Madh, 3.  Commander-Komandar, and 4.  Knight-Kalorës) and a medal, and was limited to six ordinary recipients of Albanian nationality, and not awardable to foreigners.  It was remodelled in 1932 and reduced to three classes (1.  Grand Cordon with star-Kordon i Madh me Yll 2.  Commander-Komandar, and 3.  Knight-Kalorës) and remained to be limited to only six ordinary recipients of Albanian nationality, and not made awardable to foreigners,
Answer: English