Question: The Aeolian Singers are based in the English county bordered by which county on its north?
Related documents: [0]  [DOC] Hertfordshire ( ; often abbreviated Herts) is a county in southern England, bordered by Bedfordshire to the north, Cambridgeshire to the north-east, Essex to the east, Buckinghamshire to the west and Greater London to the south. For government statistical purposes, it is placed in the East of England region. [END] 
[1]  [DOC] 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. [END] 
Answer: 
Bedfordshire
Bedfordshire