Critical care environments are known for provoking anxiety, pain, and sleeplessness. Often, these symptoms are attributed to patients' underlying physiological conditions; life-sustaining or life-prolonging treatments such as ventilators, invasive procedures, tubes, and monitoring lines; and noise and the fast-paced technological nature of the critical care environment. This, in turn, possibly increases length of stay and morbidity and challenges the recovery and healing of critically ill patients. Complementary therapies can be used as adjunctive therapies alongside pharmacological interventions and modalities. One complementary therapy with promise in critical care for improving symptoms of anxiety, pain, and sleeplessness is music. A review of current literature from Ovid MEDLINE, Cumulative Index to Nursing and Allied Health Literature, and PubMed was conducted to examine the evidence for the use of this complementary therapy in critical care settings. This review presents the evidence on effectiveness of music for the symptom management of anxiety, pain, and insomnia in critically ill adult patients. The evidence from this review supports music in symptom management of pain, insomnia, and anxiety in critically ill patients. This review provides practice recommendations, generates dialog, and promotes future research. This review is part I of a 2-part series that focuses on evidence for use of music, aromatherapy and guided imagery for improving anxiety, pain, and sleeplessness of patients in critically ill patients.