Johan Reuter Birtwistle's opera The Minotaur. Johan Reuter Johan Reuter (born 1969) is a Danish baritone and opera singer. Reuter was born in Copenhagen. He studied at the Royal Danish Academy of Music and at the Royal Danish Opera Academy. He has been a member of the ensemble at the Royal Danish Opera since 1996. His principal appearances at the Royal Danish Opera are the Mozart roles Leporello and Don Giovanni in "Don Giovanni", Figaro in "Le nozze di Figaro", Papageno in "Die Zauberflöte" and Guglielmo in "Così fan tutte", the Verdi roles Posa in "Don Carlo" and the title roles in
Piano concertos by Wolfgang Amadeus Mozart it was probably J.C. Bach, whom Mozart admired, who introduced the structural innovation of allowing the keyboard to introduce new thematic material in its first entry. Concertos Nos 1–4 (K. 37, 39, 40 and 41) are orchestral and keyboard arrangements of sonata movements by other composers. The next three concertos (K. 107/1, 2 and 3), which are not numbered, are arrangements of piano sonatas by J.C. Bach (Op 5. Nos. 2, 3, and 4, all composed by 1766). Based on handwriting analysis of the autographs they are believed to date from 1771–72. Concerto No. 5, K. 175 from 1773 was