OK, back to the 40's: This 1949 instrumental bluegrass classic was written by Earl Scruggs and first recorded by Flatt and Scruggs. Considered one of the most challenging 5-string banjo pieces. Used during chase scenes on "Bonnie and Clyde" in '67. Peaked at #55 Pop and at #58 Country. Scruggs' re-recording in 2001 with Steve Martin on 2nd banjo won him a Grammy the following year. It is on the Library of Congress' National Recording Registry.
Yesterday's answer: "Rain" by The Beatles. BINGO! One of my Beatles faves. Paul's bass work is beyond words. Killer video - still can't believe there's only 2 left. http://www.youtube.com/watch?v=bdrGS__yg6Q