In 2005 de Cou was named NSO at Wolf Trap Festival Conductor and will start his 15th season with that organization in the summer of 2019.

He was appointed the music director of the Pacific Northwest Ballet starting with the 2011-2012 season.

[2] In 2013, he was described by New York Times critic Alastair Macaulay to be "probably...America’s finest ballet conductor.

De Cou has recorded extensively including world premiere recordings of Claude Debussy's original version of Printemps Suite Symphonique, the orchestral version of Suite Bergamasque, Charles Griffes's The Kairn of Koridwen, and Elliot Goldenthal's Othello (ballet).

For his ongoing work with NASA, de Cou was awarded the NASA Exceptional Public Achievement Medal by Administrator Charles F. Bolden, Jr. at the NSO at Wolf Trap performance of The Planets in July 2012, the first musician to receive that honor.