These cello concertos of Carl Philipp Emanuel Bach were long thought to be transcriptions of harpsichord concertos, but some research has suggested that the cello versions may have come first. In these performances by fearless cellist Nicolas Altstaedt, they certainly seem suited to the cello. Bach delights in unexpected contrasts, and Altstaedt, with his slashing, vibrato-free lines, plays them up to the maximum. His performance, as usual, may be a bit much for some, but in this case he seems to have a strong connection to the music, one backed up by the historical-performance group Arcangelo under Jonathan Cohen. Sample any one of the three opening movements. Each concerto is in the conventional three movements, but beyond that there is little similarity; the music is remarkably free formally. Hyperion uses a church to produce sound a bit too brittle for a performance whose expressive qualities could have stood on their own, but the music is clear, and the compositions are brilliantly experimental.