Previous research has found that young adults exhibit patterns of poor sleep, and that poor sleep is associated with a host of negative psychological consequences. One potential intervention to improve sleep quality is listening to music at bedtime. While there exist previous works investigating the efficacy of listening to music as a form of sleep aid, these works have been hindered by statistically weak designs, a lack of systematic investigation of critical characteristics of music which may affect its efficacy, and limited generalizability. In light of the limitations in the existing literature, a 15-day randomized cross-over trial was carried out with 62 young adults. Participants completed five nights of bedtime listening to each condition (happy music vs. sad music vs. pink noise, which acted as an active control condition) over three weeks. Upon awakening each morning, participants rated their subjective sleep quality, current stress, positive and negative affective states, and current life satisfaction. Frequentist and Bayesian multilevel modeling revealed that happy and sad music was both beneficial for subjective sleep quality and next-morning well-being, compared to the pink noise condition; potential nuances are discussed. The current study bears potential practical applications for healthcare professionals and lay individuals.