For Christmas, I received the gift of "Schott's Almanac, 2007", from a dear relation. Among the many interesting items listed in this fascinating volume is a piece about the world's slowest concert recital...which is scheduled to take some 639 years to perform! Of course, this means that it contains, for the most part, silence!
I've found a link to this subject on a page from "The Times Online" of January, 2006....
http://www.timesonline.co.uk/article/0, ... 30,00.html