Aimard is best-known as an exponent of contemporary music, Harnoncourt, as a Founding Father of the period instrument movement. Both bring elements of their contrasting backgrounds to this provocative set: Aimard, in the lucidity and transparency of his playing, Harnoncourt, by rooting Beethoven within earlier traditions. But such templates don't always apply here, since they also utilize such ultra-Romantic gestures as wide tempo fluctuations, often from one measure to the next, elongated pauses, unexpected accents, among others. Such a diversity of interpretive stances takes getting used to, but the effort's worthwhile as these discs make something fresh and new out of familiar repertory pieces.

The first two concertos fare best, and the "Emperor" is also striking with its blend of clear textures and heroic gestures that likely surprised the composer's contemporaries with their boldness. In No. 3, lyricism sometimes shades into lingering, and the famous dialogue between growling orchestra and poetic piano in No. 4 is tame alongside most versions. Overall, the pair generally favor spacious tempos--the opening Allegro con brios of the first three concertos don't have much brio, and slow movements are slower than the norm, although those fluctuating internal speeds keep total timings within the "normal" range. But then, the goal of these artists is to restore a spirit of adventure and spontaneity to Beethoven, and they've certainly succeeded. --Dan Davis