sentences:  After 1777 he again falls into obscurity until his last verifiable appearance during some concerts in London in 1791.The date of his death is not known, but is believed to have been shortly after his performances in London.Demachi is listed as a composer of a significant number of works, including four symphonie concertante, eighteen duo sonatas, fifty-six trio sonatas, a pair of orchestral overtures and six string quartets listed as "for orchestra."