A Brazilian musician who has been dead for more than a decade is top of the pops in the United States thanks to Melbourne's Wouter ''Wally'' de Backer, better known as Gotye.

The Brazilian guitarist and composer Luiz Bonfa, who died aged 78 in 2001, is credited as the co-writer of Gotye's single, Somebody That I Used to Know, which has become the first Australian single to top the main US chart since Savage Garden's I Knew I Loved You in January 2000.

Bonfa was a pioneer of Brazilian jazz and contributed a number of songs to the soundtrack of Marcel Camus' 1959 cult film, Black Orpheus. His track, Manha de Carnaval (Morning of Carnival), from the film has become a jazz standard.

However, it is a mere two notes from his 1967 song Seville that have put Bonfa at the top of the US charts - and sent a welcome stream of royalty payments into the coffers of his estate.

The D and C notes, played on a nylon-string guitar, that start the bossa nova track, Seville, form the spine of Gotye's song, a debt he has readily acknowledged.

''That Luiz Bonfa sample directly prompted the first line of lyrics,'' Gotye told American music industry bible Billboard last week. Although the snippet used in the song is minimal, David Vodicka, Gotye's Melbourne-based lawyer, confirmed the Bonfa estate received a split of royalties from the song rather than a straight fee for use.

The song has sold 542,000 digital copies in the US in the past week, the fourth highest tally on record since tracking of digital sales began in 2003.