A personal view of early soft-mode history

The early history of soft modes, preceding Cochran's work, is reviewed. There were many precursors, but neither the authors involved, nor the books and review articles, appreciated the importance of the notion. The history of the work at IBM is reviewed in particular detail, with emphasis on the relation to von Neurnann's proposal for computers, based on parametrically excited nonlinear circuits. © 1987, Taylor & Francis Group, LLC. All rights reserved.