''David found before him a striking redhead with shoulder length hair dressed in a long black dress and black waist length jacket. She strode in boldly and seeing the open fiddle case lifted the fiddle straight out. She tightened the bow and then began to tune the strings. David stood by transfixed; such energy such purpose. She was the first one to even think of playing it. She began to play, warm up exercises, stopping to adjust the strings here and there. Then she launched into a piece of music he was familiar with. She seemed lost in the piece, a picture of concentration. She suddenly stopped and looked at her watch. ''Fine,'' she said, ''how much?