The RAI dossier `` Argo 16 - Un mistero mai chiarito '' , however , concluded Coming_to_believe that the cause of the crash Catastrophe will likely remain a mystery .

The first edition of the Sanremo Music Festival , held Hold between 29 and 31 January 1951 , was broadcast Expressing_publicly by RAI 's radio station Rete Rossa and its only three participants were Nilla Pizzi , Achille Togliani and Duo Fasano .