Listen to Norma : Act 1 "Casta diva" [Norma] online. Norma : Act 1 "Casta diva" [Norma] is an Unknown language song and is sung by Maria Callas. Norma : Act 1 "Casta diva" [Norma], from the album 40 Most Beautiful Arias (international version), was released in the year 2008. The duration of the song is 6:52. Download Unknown songs online from JioSaavn.