It's hard to believe, but this is the 50th anniversary of Das Alte Werk (Old Works), a label that helped pioneer the early music and period instrument movement.

For that reason, Warner Classics is re-issuing a series of important CDs.

The Alte Werk label - along with Archiv, Harmiona Mundi, L'Oiseau-Lyre and many others - helped to pioneer the early music movement and period instrument playing that is today taken for granted.

Das Alte Werk was inaugurated in 1958 with the release of 7-inch discs of Gregorian chant and music by Guillaume de Machaut, and quickly gained a reputation for historically informed, high-quality recordings. LPs of harpsichord sonatas by Scarlatti, Concerti grossi by Handel and Partitas for unaccompanied violin by Bach soon followed. And then came CDs, which helped the market to explode with specialty labels and rarely performed works.

On Das Alte Werk, the collaboration of such now well known artists as Nikolaus Harnoncourt, Gustav Leonhardt, Frans Bruggen and Jaap Schroeder ushered in a new era: the rediscovery of the authentic sound of period instruments and scholarly research into original sources.

Added to the first 10 CDs from the series released last November, are five new releases in stores:

"Music at the Court of Mannheim" by Nikolaus Harnoncourt and the Concentus Musicus Wien (Vienna)

J.S Bach's "Goldberg" Variations, BWV 988 by Gustav Leonhardt.

Luigi Boccherini's Cello Concertos with Jaap Schroeder and the Concerto Amsterdam.

Henry Purcell's opera "Dido and Aeneas" with Nikolaus Harnoncourt and the Concentus Musicus Wien.

J.S. Bach's Mass in B minor, BWV 232, with Nikolaus Harnoncourt and the Concentus musicus Wien.

I particularly like period playing of J.S. Bach's vocal and instrumental music (with the exception of the keyboard works, which I generally prefer dome with the modern, more singing piano than the twangy harpsichord) as well as Vivaldi's and Handel's string music.

But I really prefer modern instruments in orchestral music and chamber music by Haydn, Mozart, Beethoven and Schubert.

I really don't know how to square that circle. Maybe I go with whatever sounds best to my ear, even if that means I am inconsistent.

Anyway, you can find more titles and information at Amazon.com. and www.dasaltewerk.com.

Do you prefer period instruments performances of early music, or modern instrument versions?

Which early music groups and individual musicians, from the past or currently, are your favorites?

Are there early music recordings you highly recommend? Or detest?

Some critics think early music players today allow for more individual expression within authentic instruments or historically informed performance practices. How do you think the performances of early music have evolved over the past several decades?

Let Art Talk know.