This study was conducted to determine how listeners derive global evaluations of past musical durations from moment-to-moment experience. Participants produced moment-to-moment affective intensity ratings by pressing a pressure-sensitive button while listening to various selections. They later reported the remembered affective intensity of each example. The data suggest that the assumption that remembered affect equals the sum of all momentary affects fundamentally misrepresents how listeners encode and label past affective experiences. The duration of particular rather than uniform episodes contributes minimally to remembered affect (duration neglect). Listeners rely on the peak of affective intensity during a selection, the last moment, and moments that are more emotionally intense than immediately previous moments to determine postperformance ratings. The peak proves to be the strongest predictor of remembered affect. We derive a formula that takes moment-to-moment experience as input and predicts how listeners will remember musical affect. The formula is a better predictor of postperformance affect than any other on-line characteristic considered. Last, the utility of the formula is demonstrated through a brief examination of compositional decisions in a string quartet movement by Borodin and one typical format of four-movement symphonies from the classical period.