Fans' scrap-books are the best way to judge how successful one was at a certain time. Here's some examples of how successful Italian music was in Brazil between 1963 and 1967.
Rita Pavone was absolute Number One
Nico Fidenco one of the 1st Italian acts to break into the Brazilian market with 'Legata a un granello di sabbia'
Gianni Morandi was #1 with 'In ginocchio da te' - John Foster was #1 with 'Amore scusami'
Sergio Endrigo visited Brazil a few weeks before the military coup - Michele was in S.Paulo in 1965
Catherine Spaak's 'L'esercito del surf' was popular but Wanderlea's cover was even more- Giancarlo Guardabassi's 'Se ti senti sola'
Edoardo Vianello visited Brazil twice - Pino Donaggio was king with 'Io che non vivo'
Nico Fidenco's 'Ciò che rimane alla fine di un amore' - Mina's 'È l'uomo per me'