Walter Pridham didnâ??t so much sweep his future wife off her feet as bowl her over.It was 1952, and they were both singing in the choir at Pres House, the Presbyterian student chapel on the UW-Madison campus. He was 21 and in the Air Force, stationed at Truax Field in Madison. She was an 18-year-old nursing student. After practice one night, he came around a blind corner from the coat room and crashed into her. As he picked her up, he invited her to coffee, thus beginning their courtship. Pres House has rarely been far from their thoughts ever since. Now, 58 years later, the Pridhams have donated $72,000 to replace the pipe organ in the chapel. Of the total, $22,000 is an outright gift, and $50,000 is a matching grant, part of an effort to raise $125,000 for the Pres House music program.