I was on hold waiting for customer support on the phone. The music they had playing on the phone was about 20 seconds looped over and over of a baroque era piece. The very first measure sounded almost if not completely identical to Brandenburg Concerto No. 1 Mov. 1 but then went on to something completely different. The orchestration was the same (horns, oboes, string orchestra). I'm wondering if maybe it's a sinfonia from a Bach cantata I've never heard before.

Anyone have any idea what I might have heard? I can't get it off my mind!