Video 1:
Video 2:

These two videos above were recorded to celebrate 50 years since William Cosby won the USA Championships.
Video 1: Mephisto Waltz, Franz Liszt, arrangement by Anthony Galla-Rini & William Cosby.
Video 2: Scarlatti Sonata in E Major L 430

William Cosby passed away on July 7, 2016 and was USA national champion (ATG, 1964, 65, 66, 67) winning 2nd place at the Coupe Mondiale in 1964 (Canada) and 3rd place and the Coupe Mondiale in 1965 (Malta).

William Cosby was the winner of three Accordion Teachers Guild national titles and two American Accordionists Association titles. He was also the Instructor of Cadet of Music and the Music Director and Conductor of the West Point Glee Club during his time at the United States Military Academy.

Cosby played both pop and classical jazz styles as an accordionist. He also played the piano, conducted symphony orchestras and produced demos for Warner and Atlantic record labels.

Fuller information in the USA News.