You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Newcastle_upon_Tyne

Context:
Musicians Eric Burdon, Sting, Mark Knopfler, Alan Hull, Cheryl Cole and Neil Tennant lived in Newcastle. Hank Marvin and Bruce Welch were both former pupils of Rutherford Grammar School, actors Charlie Hunnam and James Scott, entertainers Ant and Dec and international footballers Michael Carrick and Alan Shearer were born in Newcastle. Multiple circumnavigator David Scott Cowper, Nobel Prize winning physicist Peter Higgs, and former WWE NXT champion Neville were born in the city. John Dunn, inventor of keyed Northumbrian smallpipes, the most characteristic musical instrument in the region, lived and worked in the city.

Question:
What did John Dunn invent?

keyed Northumbrian smallpipes