Maryrrf, you actually asked two questions. One was, "What are the techniques, characteristics, etc. that distinguish a great traditional singer" and one was, "when they judge traditional singing competions, what are the judges looking for?" They may not have the same answer!

Also to some extent the answer depends on whether you talk about "a traditional singer," who sings many kinds of songs, or a singer in a specific tradition.

It's a good question, with a thousand answers. Here are a few of mine.

I guess the first thing is that the person's voice makes me want to listen. What else?

These days I look for people who stay with each and every song; the style and technique, or the desire to show off their singing, never outweigh the song. If they are singing in a given traditional style, I listen to how comfortable they are in that style. I listen to whether their music sounds "plastic" and "media-contaminated," or whether it sounds as if it comes from a deep feeling for the song. I listen for whether they carry the message and keep me involved or whether they lose me halfway through the song.

Energy makes a difference. Some singers have a vitality that affects their listeners, makes you feel more alive when you hear them.

Personally I also like a singer "in the tradition" to sound as if they have listened to traditional singers, i.e. source singers, and absorbed some of their techniques and ways of making music.

Rita F