In recent years, the analytical concept of structural depth has been subjected to intense critical scrutiny. But amid debates over the relative merit of depth- and surface-oriented modes of listening and analysis, surprisingly little attention has been devoted to the history of the two terms in music journalism. Focusing on the period around 1800, this article examines the entry of the term "depth" into German literature on music and explores the metaphorÕs diverse, even contradictory, meanings. Writers like Wilhelm Heinrich Wackenroder and E. T. A. Hoffmann endorsed the idea, prominent in German Pietism and the criticism of Johann Gottfried Herder, that sound was uniquely able to access the deepest regions of subjectivity. At the same time, such writers began to imagine a musical inner space uncannily similar to the inner space of the listening subject. Unlike earlier aestheticians of a poetic bent, Hoffmann thought that the "deepest" works--works that stirred the soul with special force--required the critic to "penetrate" their "inner structure." Given that earlier technical discourse had treated music essentially as a linear sequence of periods, HoffmannÕs writings exhibit a momentous shift in perspective from the sequential to the vertical. By adding a new dimension to music complementing its axis of horizontal or temporal unfolding, Hoffmann imported the full spectrum of depthÕs meanings, ranging from the scientific to the spiritual, the rational to the irrational, into the modern notion of the masterwork.