“The somber, elegiac tones before President Obama’s oath of office at the inauguration on Tuesday came from the instruments of Yo-Yo Ma, Itzhak Perlman and two colleagues. But what the millions on the Mall and watching on television heard was in fact a recording, made two days earlier by the quartet and matched tone for tone by the musicians playing along.

The players and the inauguration organizing committee said the arrangement was necessary because of the extreme cold and wind during Tuesday’s ceremony. The conditions raised the possibility of broken piano strings, cracked instruments and wacky intonation…” via NYTimes.