Two experiments were conducted in order to test predictions derived from Berlyne's theory of aesthetic preference. According to the theory, preference is an inverted-U function of arousal potential; the determinants of arousal potential are summed, with the consequence that an increase in the amount of one determinant leads to a decrease in the maximally preferred level of other determinants; and collative properties, such as dissonance, are the most important predictors of preference. The experiments supported none of these predictions. Preference tended to be related to its determinants by monotonic or U-shaped functions. The predicted trade-off among the determinants of preference was not clearly present. Semantic factors rather than collative properties were the most important determinants of preference. In Experiment 1, uncertainty was related to preference in an inverted-U manner, but it was shown that this may be an artifact of a U-shaped relationship between preference and melodic typicality. In Experiment 2, it was found that subject-rated meaningfulness is highly related to preference for melodies, whereas subjectively perceived complexity is essentially unrelated to preference. The results are explained in terms of a cognitive theory of aesthetic preference.