Norberto AnÃ bal Napolitano ( La Paternal , Buenos Aires , March 10 , 1950 â `` LujÃ n , February 24 , 2005 ) guitarist , singer and argentine rock , blues and metal producer . Pappo is the pseudonym of Argentine blues and metal\/rock musician Norberto Napolitano ( Buenos Aires , 10 March 1950 â `` LujÃ n , Buenos Aires Province , 24 February 2005 ) .