For nearly 150 years Bach’s ever-popular Concerto in D minor for harpsichord (BWV 1052) has been regarded as a transcription of a much earlier violin concerto. Numerous published reconstructions of this ‘lost original’ have appeared, as well as many modern recordings. However, previous violin reconstructions have proved unsatisfactory from both a musicological and a violinistic standpoint, and some leading scholars have even doubted that the violin was the original solo instrument.

This late...