I myself prefer the normal key but in this recording they've shifted the notes up 1/16 octave. It makes it sound a lot like Vivaldi, and not like the classical Bach I have come to know and like. It's still appreciable though, and the last concerto on the disc is of superb interpretation. Another kudos to them: the 2nd movement of the Concerto No. 1 in A Minor (track 5) is the best I have ever heard. Fabulous. Overall, a recommended disc if you don't own a Bach violin concerto collection yet. However, for the classically minded, the shift up 1/16 octave can distort how Bach intended for it to sound. For that reason you may want to look into some great performances (there are many) by Itzhak Perlman and Isaac Stern that are a bit less creative but no less spectacular.