the album also includes '' in re don giovanni , '' nyman 's first composition for the band , which is based on the first sixteen bars of '' madamina , il catalogo è questo '' from don giovanni , six selections from peter greenaway 's film , drowning by numbers , in which he was instructed to base the music on the slow movement mozart 's sinfonia concertante k. 364 , and two duets and an aria from nyman 's television opera , letters , riddles and writs , in this recording featuring bass andrew slater as leopold mozart and contralto hilary summers as wolfgang .