I feel that Mudcat friends would like to know this exceptional artist who was born and lives in Buenos Aires, Argentina, my country.
You will find him here:
http://www.gabrielgratzer.com.ar/english/index1.htm

Gabriel is one of the very few musicians in Argentina dedicated to the serious study of the Gospel and Country Blues, and a brilliant interpreter. From his site you can download many delightful samples in MP3.

He teaches harmony and stylistics to the director of the vocal ensamble where I sing, so he is transmitting his knowledge to the ensamble too.

Un abrazo - Andrés