Violist David Aaron Carpenter of the US plays the 'Macdonald' Viola by Antonio Stradivari, made in 1719, at Sotheby's gallery in New York March 27, 2014. The 'Macdonald' Viola, a rare Stradivari viola considered to be one of the finest in existence, is expected to fetch more than $45 million in a sealed bids sale this spring, which would set a world record for the most expensive musical instrument ever sold. The viola is the first to be on the market in 50 years, according to Sotheby's auction house.[Photo/Agencies]