As every year since 2005, the municipality of Rosny-sous-bois is organising the MusicOparc festival.

A free, open-air festival, MusicOparc offers an eclectic, international programme, every weekend between 25 June and 24 July 2011. This year, MusicOparc will take place on Saturdays 25 June, 2 July and 9 July, followed by Sundays 17 and 24 July.
While Saturday 25 June will see Femi Kuti take the stage set up in the Decesari landscaped park, 2 July will be a "Jamaica special" night with Lee Perry, Max Romeo and The Congos. On Saturday 9 July, Orlando Poleo + Martha Galarraga will perform, and finally Sundays 17 and 24 July will be devoted to electronic music with the Dimanches électROSNYques (programme still being finalised).