B Hollow stock and Drones.
BBC Your Place And Mine radio interview with Martin Preshaw, by Anne Marie McAleese, on October 31, 2015.
http://bbc.in/1PXs56L Interview begins at 19:24.
"The 'pipes of the elbow' as they're called sometimes, because of the way they're played and doing that isn't easy - never mind, making a set of them, very complicated instruments. Only about 6 or 7 people in the world are real, expert pipem...