While not including sound files, this music source from the Orthodox Church in America is remarkable in every way: http://www.oca.org/MDmusic.asp?SID=13
You can't go wrong with music from the Eastern Church. It always focuses on the text and is overwhelmingly accessible to singers. It takes a bit of a sales job to get choirs behind it because some of your singers, usually the weakest, will say, "That's too easy." Yeah, right. Ignore them and go right ahead.
Znammeny chant should be sung with the same rhythmic flexibility as western plainchant. One of the varieties of monophony in the Slavic Christian world, it largely disappeared from cathedral and parish use with the rise of 4-part Western European-style Obihod settings in the 18th century. Because of the obvious lack of mixed choirs in monasteries and convents, it hung on there and has now made a comeback (well, "starting to make a comeback" would be more accurate) in wider circles.
To hear chant from the Valaam monastery in a similar style, you can check out Church Singing . And while you're there, take a look at the pictures. It's a wonderful way to waste time prayerfully.
To participate in the discussions on Catholic church music, sign in or register as a forum member, The forum is a project of the Church Music Association of America.