CHICAGO -- The Chicago Tribune called her "the marvel of the generation." She was "more amazing than Yehudi Menuhin when he first appeared in New York as a boy of 8," wrote the New York Herald Tribune, while another critic summed up the phenomenon with three extraordinary words: "Not since Mozart." She was, quite simply, the most famous child prodigy of her day, more renowned than the young Isaac Stern, more spectacular in her precocity than Jascha Heifetz. Today, pianist Ruth Slenczynska looks back on those early years with both pride and regret. "I certainly don't recommend the stage for anyone," says Slenczynska, who, nevertheless, still tours the world's stages. "To this day, I do not love the stage -- I learned long ago that performing on stage and making music are not entirely compatible experiences." Slenczynska (pronounced Slen-CHIN-ska) learned the hard way. Though the world considered her something of a divine genius, she actually was a sweet little girl being driven by an ambitious father. When Slenczynska's autobiography, "Forbidden Childhood," came out in 1957 (it's now out of print), she dealt a stunning blow to the myth of the child prodigy. A few indelible excerpts: "Every time I made a mistake (while practicing), father leaned over and, very methodically, without a word, slapped me across the face ... If I slipped in the middle of the C major scale, I would have to start all over again. And for each slip a matter-of-fact slap, till, I suppose, I came to accept it as part of the natural order of things." "Father was making me practice nine hours a day, every single day of the week. No mistake ever went unpunished. The moment I missed a note I got a whack across my cheek. If the mistake was bad enough, I was almost hurled bodily from the piano." "During practice, a sickening thought crossed my mind. 'What happens,' I asked Father, 'if I make a mistake in the middle of my concert?' and Father very obligingly told me that people went to concerts with bags full of rotten eggs and vegetables, particularly tomatoes, and if you hit a wrong note, these rotten eggs and vegetables, particularly tomatoes, would come flying at you. "Sure enough, the very next day, I missed a note in going over the Beethoven variations. Without a word, Father disappeared through the sliding door, strode into the kitchen, opened the refrigerator, reappeared through the sliding doors and threw a tomato at me. I ducked and the piano got it. Mother was furious because of the mess." "Whatever the merit of my playing, it wasn't the result of any phenomenal or miraculous gift. I was merely doing what I was taught very rigorously to do ... The results, such as they were, were dearly won by a driving, incessant process of teaching and learning." How could it be? How could a child so extravagantly praised by critics and revered by audiences be little more than a musical automaton? Why was everyone fooled? The answer is that not everyone was -- only those who were so dazzled by Slenczynska's youth as to cease listening critically to her art. A few musicians of depth, however, knew otherwise. "I remember when, as a young girl, I was taken to play for Rachmaninoff," says Slenczynska. "He asked me to play a Chopin etude, and when I finished, he replied, 'Poor Chopin,' because I missed so many notes. "He said my fingers were like overcooked spaghetti. "You see -- all those years I was really doing a big fake job; no child can play these pieces really well, or with real musical insight." More important than the incompleteness of Slenczynska's pianism, however, was the human toll she was paying. When other children were playing games with their friends, Slenczynska was virtually chained to the keyboard, shuddering in fear of her father. It will come as no surprise that by the time Slenczynska reached her middle teens, she hit a major breakdown. No longer able to rationalize her father's mistreatment of her, she abruptly quit performing, severely cut down her practicing and, by age 19, eloped with her first husband, George Born (they were married for 11 years). As she walked out the door of her parents' house for the last time, her father shouted, "You'll never play two notes again without me." It was years before she did, at least in public. Instead, she became a piano instructor at various small colleges, eventually inching her way back onto the concert platform (she married her present husband, James Richard Kerr, about 20 years ago; there were no children from either marriage). Though today, at 63, she does not forget her sad past, she doesn't dwell on it. "I suppose you could say I'm an optimist," says Slenczynska. "I'm always ready for the next concert or the next tour that will come along. The trick, you see, is to never look backward. Ask me what I played at my last concert, and I'll have to stop and think -- the past does not interest me. "You see, I forgave my father a long time ago," says Slenczynska of Josef Slenczynski (Ruth changed the last letter of the family name as a gesture of independence). "Before Father died, I heard that he wasn't well, and even though I was a piano teacher making very little money, I rushed to Salt Lake City, where my parents were living, to visit him, to tell him that I forgave him. "He wouldn't see me, but he told my mother that it was he who would have to forgive me. Deep down, though, I think he knew what he had done, and at least he knew that I had come to see him one last time. "As for my mother, she came to hear a concert of mine just a few weeks ago in Gainesville, Ga. She had to come all the way from Atlanta, where she lives, by train. I think she's proud of me." When eager parents bring their precocious children to Slenczynska today (she teaches at Southern Illinois University in Edwardsville), she is quick to share her advice. "I tell them that if the young person loves music -- absolutely cannot live without being a musician -- then it's okay for them to study seriously," she says. "But if the child or their parents are looking for money or fame, they should not. Fame is nothing, and money disappears (Slenczynska's father took hers). "But if you desire to learn all the beautiful piano music and to see the whole world, that's something else. And perhaps her most ardent dream is that no child -- regardless of how gifted -- should sacrifice the greatest gift of all, a happy childhood. "Sometimes people are surprised that I've been so open about what happened to me, and that I went so far as to put it in a book and to talk about it," says Slenczynska. "I do it because I feel that if I have saved one little kid from what I went through at the hands of a father who meant well but just didn't know enough, it was worth it. "I want parents to know that a pianist's career is not glamorous. They think that all you do is put on fabulous clothes and walk onstage and get a fat check and see the world. "Well it isn't that at all. It takes a lot of intestinal fortitude to walk out on that stage. "My experience as a child prodigy changed me, but I'll tell you one thing: There isn't a thing that can happen to me now that I can't surmount. "I've experienced it all."