This is the second of two menuets found in Bach's Partita No. 1 in B-flat major (Opus 1). I've always enjoyed this brief section of the work and it includes some tricky finger work despite the deceitfully simple harmonies. Bach certainly had a way of emphasizing the subtle harmonies to invigorate the soul! Bach himself wrote the following on the title page of the first volume of the Clavierubung (which consists of the 6 partitas):
Keyboard Training, consisting of Preludes, Allemandes, Courantes, Sarabandes, Gigues, Menuets and other Galanteries, dedicated to Music Lovers for the Pleasure of their Minds