Before catgut violin strings were a gleam in Christopher Hogwood's eye, there was Neville Marriner and the Academy of St. Martin-in-the-Fields. A chamber orchestra in an era before historically informed performance practice, the Academy of St. Martin-in-the-Fields was a virtuoso ensemble light of tone, clean of intonation, and brisk of tempo; they specialized in energetic and objective performances. In this three-disc 2007 collection combining a 1964 recording of Handel's 6 Concerti Grossi, Op. 3, with a 1968 recording of the same composer's 12 Concerti Grossi, Op. 6, Marriner and the Academy turn in performances marked by sharp, snappy conducting and bright, brilliant playing. The Opus 3 set is very impressive with its buoyant Allegros and expressive Largos. But the Opus 6 set is even better with the same qualities plus superlative solo violin playing from such Academy stalwarts as Iona Brown, Alan Loveday, and, in four concertos, Marriner himself. George Malcolm is an alert harpsichordist in Opus 3, but Thurston Dart, while not as agile, is more penetrating in Opus 6. First released on Argo LPs in justly celebrated stereo sound, they sound as fine if perhaps a bit louder in this digital remastering. Listeners who like Baroque music but find the tone and tuning of period instruments a strain over the long haul will surely enjoy these recordings.