The Kronos Quartet is a highly-regarded string quartet that tends to specialize in 20th Century composers. They, too, have seen the connection between the past and the present.

In its disc entitled “Early Music (Lachrymae Antiquae),” the Quartet intermingles medieval and renaissance tunes by composers such as Guillaume de Machaut, John Dowland, Perotin and Hildegard von Bingen with compositions by Twentieth Century and contemporary composers including Arvo Part, Harry Partch, John Cage and Alfred Schnittke.

The result is illuminating. By intermingling the pieces, the Quartet allows the listener to hear just how closely related they are. Without artificial emphasis by the Quartet, the ear tends to hear the subtle dissonances present in earlier works and the tuneful beauty of modern ones. It’s sometimes hard to tell them apart.

This is no academic exercise, however; it is simply beautiful. Most of the tunes are slow; the overall impression is one of intricate jewels that can either awe (if you study them carefully) or simply diffuse a wonderous light (if you listen less attentively). Even listening to them as background music (which you certainly can do -- I often play it for unsuspecting dinner guests), every once in a while you look up, shake your head and smile.

I have listened to this cd scores and possibly hundreds of times. It never ceases to amaze me.

• Kronos Quartet: Early Music