ROYAL MUSIC COLLECTION. Bach (Johann Christian). Magnificat in C major; circa 1758 . Autograph . �A 8 Pieno con strom:�. In score, voice parts only, the rest unfinished. Similar to but not identical with R.M.22.a.13. Undated, but apparently circa 1758. Paper. ff. 10.Johann Christian Bach, composer: Church music: circ 1758-1762: Ital, Eng: Autogr.