Donald Macleod examines Bach's musical activities during the 1730s, when on top of his regular job keeping Leipzig's four main churches supplied with cantatas, he took on a secular concert-giving role as director of the Collegium Musicum in Leipzig. Somewhere along the way, he invented the keyboard concerto. Badinerie (Ouverture/Orchestral Suite No 2 in B minor, BWV 1067) Amsterdam Baroque Orchestra Ton Koopman (conductor) Concerto in D minor for two harpsichords, BWV 1061 Kenneth Gilbert (harpsichord) The English Concert Trevor Pinnock (director/harpsichord) Der Herr ist mein getreuer Hirt, BWV 112 Katharine Fuge (soprano) William Towers (countertenor) Norbert Meyn (tenor) Stephen Varcoe (baritone) Monteverdi Choir English Baroque Soloists John Eliot Gardiner (conductor) Concerto in the Italian Style, BWV 971 Elizabeth de la Porte (harpsichord) Fugue in E flat, BWV 552 No 2 (St Anne) Christopher Herrick (organ).