El Negro Zumbon

El Negro Zumbon is credited as Music by Roman Vlad but I know this song was composed by Armando Trovajoli and sung by Flo Sandon's (Silvana Mangano sings in in playback) and this is confirmed by Trovajoli's web site http://www.trovajoli.it/scheda_ita.asp?index=11. Who is right?