Dunedin Consort - J.S. Bach: Six Brandenburg Concertos - American Record Guide

After working through Bach's major sacred choral works, John Butt has led his instrumental troops on a jaunt of their own.
There are twenty-one players in the band (including Butt himself on harpsichord), one to a part, on period instruments. Great care has been made to assimilate the latest scholarly understandings. The pitch used is A=392 Hz.

This group is in full and virtuosic command of its instruments, allowing confident plunges into risk-taking as well as lovely exploitation of the varied colors. Period instrument performances don't get any better than this.

Let's just say that this is one of the very top period-instrument recordings of the moment.