Listen to Wolf-Ferrari: Sly: Un orso in musoliera online. Wolf-Ferrari: Sly: Un orso in musoliera is an English language song and is sung by Roberto Alagna, Orchestra Of The Royal Opera House, Covent Garden, Sir Mark Elder and London Voices. Wolf-Ferrari: Sly: Un orso in musoliera, from the album Les 100 Plus Beaux Airs de Roberto Alagna, was released in the year 2013. The duration of the song is 4:54. Download English songs online from JioSaavn.