Music therapy is a non-invasive method with no side effects and can be administered independently by a nurse. Nevertheless, it should be noted that music therapy can be discontinued if any adverse effects are experienced by patients during the research process. After completing the music listening session, eye masks and earplugs, which are effective in reducing sleep problems in patients, will be applied from 11:00 p.m. to 7:00 a.m.

All patients will be asked to complete the DAÖ at 10:00 PM and 10:30 PM. The RCUÖ will be requested to be completed by all patients between 8:00 AM and 9:00 AM the following morning.

Control Group: Patients in the control group will receive routine treatment and care in the coronary care unit (CCU). Patients presenting with MI are admitted to the coronary care unit from the emergency department and the cardiology outpatient clinic. In patients admitted to the CCU, preparations are made for percutaneous coronary intervention (PCI) and admission procedures by evaluating electrocardiography (ECG), blood parameters (CK-MB and troponin), and pain symptoms. These preparations include obtaining the patient's medical history and necessary consent, establishing an intravenous line, measuring and monitoring vital signs, and recording the ECG and adding it to the file. In patients undergoing PCI, the femoral sheath is not removed for four hours due to the heparin infusion administered. After the femoral sheath is removed by the physician, pressure dressing is applied to the procedure site and a sandbag is placed to control bleeding for six hours. During this time, patients are placed in a supine position. Depending on the clinical condition and hematological values of the patients, they are monitored in the coronary care unit for one or two days and then transferred to the cardiology clinic.

In the coronary care unit, in order to control patients' anxiety levels or improve their sleep quality, after care, treatment, and daily blood sampling procedures are completed, lighting is reduced after midnight, except in emergencies, to facilitate patients' transition to sleep. However, eye masks or earplugs are not routinely used for patients.

Study Group: In addition to the clinic's routine treatment and care practices, patients in the study group will listen to music for 30 minutes at 10:00 p.m. on their first night in the coronary care unit using wireless Bluetooth headphones (JBL TUNE 520BT, Harman International Industries, USA) provided by the researcher (MY). The volume of the music will be adjusted according to the patient's preference. Patients in the study will listen to the CD "Music and Health Series: Tümata-Receptive & Meditative Uşşak Mode" prepared by the Turkish Music Research and Promotion Association (TÜMATA), which is said to provide calmness and relaxation and has previously been shown to be effective in reducing preoperative anxiety. The Uşşak mode has a tempo of 60-80 beats per minute and provides relaxation by calming the heart. The CD used contains an instrumental piece without lyrics in the Uşşak mode, which fits the definition of "sedative music". The piece features improvisation based on rhythm and the sound of water, performed with the ney, rebab, çeng, ud, dombra, and rubab. In addition to evoking a sense of peace and tranquility, the Uşşak mode supports feelings of self-confidence and determination thanks to its hidden pentatonic structure . The Uşşak mode is reported to give individuals a desire to laugh, a feeling of relaxation, joy, strength, and heroism; it is also reported to be beneficial for sleep and rest processes. Its effect is said to be particularly pronounced from dawn to noon, at sunset, and on Thursdays; it is also said to be beneficial in alleviating pain associated with heart and foot disorders and gout. Furthermore, it is known as one of the oldest modes used to express deep love and mystical feelings .

Inclusion Criteria:

• Admitted to the coronary care unit with a diagnosis of MI,
• Aged 18 years or older,
• Conscious, oriented, and cooperative,
• Able to read and understand Turkish,
• Agreeing to participate in the study,
• Having no physical condition that would prevent listening to music,
• Having no diagnosis of hearing loss,
• Not using a hearing aid,
• Having no diagnosis of anxiety disorder,
• Not diagnosed with a sleep disorder,
• Not taking medication for anxiety or sleep disorders,
• Without mental illness,
• With a State Anxiety Scale (SAS) total score of 60 or below,
• Who agree to participate in the study (by signing the Informed Consent Form) will be included.

Exclusion Criteria:

• Admitted to the coronary care unit (CCU) for reasons other than MI diagnosis,
• Under 18 years of age,
• Unconscious, disoriented, and uncooperative,
• Unable to read and understand Turkish,
• Refusing to participate in the study,
• Having a physical condition that prevents listening to music,
• Diagnosed with hearing loss,
• Using a hearing aid,
• Diagnosed with an anxiety disorder or taking medication for anxiety,
• Diagnosed with a sleep disorder or taking medication for a sleep disorder,
• With a mental disorder,
• With a State Anxiety Scale (SAS) total score of 60 or above,
• Patients who do not agree to participate in the study (who do not sign the Informed Consent Form) will not be included in the study.

Randomized Group Assignment and Blinding The total of 64 patients (32 control, 32 intervention group) in the sample group determined by randomization will be divided into groups A and B created by the same statistician in a computer environment. The outcome of the draw will determine whether group A or group B will be the study or control group at the beginning of the study. Information indicating that the patients included in the study sample have been assigned to groups A and B according to the randomization table (Appendix 1) will be placed in an opaque envelope. This envelope will be kept by the advisor (GAU), and when the researcher (MY) goes to the patient for the application, he/she will open the envelope after filling out the "Informed Consent Form" to find out which group the patient belongs to. The researcher will be blinded to the group assignment. Since the patients in the study group included in the research will be listening to music, the patients and the researcher (MY)