In Leipzig, the Magnificat was regularly part of Sunday services, sung in German on ordinary Sundays but more elaborately and in Latin on the high holidays (Christmas, Easter and Pentecost) and on the three Marian feasts Annunciation, Visitation and Purification.
For the feast of Visitation of 1733, Bach produced a new version of his Latin Magnificat, without the Christmas hymns: instrumentation of some movements was altered or expanded, and the key changed from E-flat major to D major, for performance reasons of the trumpet parts. This version of Bach's Magnificat is known as BWV 243. The previous version including the Christmas interpolations, was given the number BWV 243a in the catalogue of Bach's works.
The chorus and instrumentation of this sacred masterpiece is one of the most elaborated in the entire period when composed: 18th century. Being one of my favourite sacred masterpieces ever, it is almost a must to have at least 3 recordings. There are certainly lots of recordings about this sacred work both using small forces (OVPP) and VvPP. Among the recordings I have at this moment:
OVPP recordings:
Pierlot / Ricercar Consort (Mirare)
McCreesh / Gabrieli Consort & Players (Archiv)
Veldhoven / The Netherlands Bach Society (Channel Classics)
VvPP recordings:
Herreweghe / Collegium Vocale, La Chapelle Royale (Harmonia Mundi)
Suzuki / Bach Collegium Japan (BIS)