Understanding how performance expression affects perceived emotion requires separating the effects of notated music from its interpretation by performers. Previous studies suggest that compositional cues (e.g., the pitches of a melody) primarily convey valence (negative–positive emotional quality), whereas performance cues (e.g., performance timing, intensity) convey arousal (low–high emotional intensity). However, these conclusions largely follow from simple single-line stimuli that lack the complexity of real-world music. To explore compositional and performance contributions to emotion in more complex works, we conducted experiments comparing participants’ ( N = 120) valence and arousal ratings of 48 recorded excerpts from a Grammy-winning pianist against parallel deadpan versions lacking emotionally expressive aspects. By comparing differences in ratings of stimuli presented in expressive and deadpan conditions, we corroborate past findings highlighting performance contributions to perceived emotion, while also providing novel insight into the relative importance of analyzed cues. Our findings reveal that removing expressive aspects (i.e., the deadpan condition) significantly affects arousal ratings of 21 excerpts, but valence ratings of only 4. Additionally, we highlight how cues differ in importance between expressive and deadpan conditions through a novel analytical approach employing elastic nets. Our analyses shed new light on how performance expression affects emotions communicated across complex musical works with different levels of compositional cues.