Not only oboists regret that no original concerto for oboe and orchestra by Johann Sebastian Bach has come down to us. But it is perfectly possible that Bach’s lost instrumental works from Weimar and Köthen also included oboe concertos, which he subsequently used in Leipzig as the basis for cantata movements and harpsichord concertos. Laborious reconstruction has proved worthwhile: Juliana Koch will present two such, grandiose, oboe concertos by Bach.