Part of my listening experience has been a coming to terms with a certain set of musical forms that I call ‘flat’. Music in flat form means music that avoids obvious or dimensionally conjunct large-scale goals, points of arrival, ‘climaxes’, sectional boundaries, and the like, and therefore has proven difficult for many listeners. It has become clear to me that this music demands a different listening approach, one at odds with the way music is typically appreciated in the concert hall. This approach is one that composers of music in flat form can facilitate through today's computer-music resources. What I present here is a specific instance of such an approach: my composition Sand, a twenty-five-minute long work for computer-synthesised and processed sounds, was composed specifically to be experienced through a computer-music interface I built in the MAX/MSP environment. This paper explores what I mean by ‘flatness’, how I came to terms with it as a listener, and how this coming-to-terms spawned the idea and construction of the interface. I then discuss the interface itself, the process of interaction with the listener, and technical aspects of the software.