A new world record was achieved on August 17, 2013 with 508 Alphorn players on the Gornergrat in the Alps of Wallis in Switzerland. This is the most Alphorn players ever gathered to perform a song on this ancient instrument. They played a song composed and directed by Gilbert Kolly “Uf em Gornergrat”. There also was another record broken with the longest Alphorn ever built and played: it measures 48 meters!

http://www.bbc.co.uk/news/world-europe-23744854