Here is the design of a clinical trial:

Official Title: Playing and Singing for the Recovering Brain: Efficacy of Enriched Social-Motivational Musical Interventions in Stroke Rehabilitation

Included conditions:
- Stroke

Study Armgroups:
- {'label': 'Enriched Music-Supported Therapy group', 'type': 'EXPERIMENTAL', 'description': 'Participants in the eMST-group will follow a 10-week program of Enriched Music-Supported Therapy. The program comprises 3 individual self-training sessions and 1 group session per week (total program duration: 40 hours).', 'interventionNames': ['Behavioral: Enriched Music-Supported Therapy']}
- {'label': 'Control group', 'type': 'ACTIVE_COMPARATOR', 'description': 'Participants in the control intervention group will follow the Graded Repetitive Arm Supplementary Program (GRASP, Harris et al., 2009). They will be asked to complete 4 weekly one-hour session for 10 weeks (total program duration: 40 hours).', 'interventionNames': ['Behavioral: Graded Repetitive Arm Supplementary Program']}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'Enriched Music-Supported Therapy', 'description': 'Home-based rehabilitation program for stroke patients aimed at improving the upper extremity motor function. The program is based on musical training, combining self-training sessions of music playing using an app for electronic tablets and music therapy group sessions.', 'armGroupLabels': ['Enriched Music-Supported Therapy group'], 'otherNames': ['Music-Supported Therapy']}
- {'type': 'BEHAVIORAL', 'name': 'Graded Repetitive Arm Supplementary Program', 'description': 'Home-based rehabilitation program for stroke patients aimed at improving the upper extremity motor function. The program comprises self-training sessions of mass repetition of movements and task-specific exercises for the upper extremity.', 'armGroupLabels': ['Control group'], 'otherNames': ['GRASP']}

Primary Outcomes:
- {'measure': 'Change in Action Research Arm Test', 'description': 'Upper extremity function measure. The measure is a 19-item test divided into four subtests (grasp, grip, pinch and gross movement). For each item, the patient is asked to perform a simple task that involves a functional movement of the affected upper limb. Each task is rated using a 4-point ordinal scale. The maximum possible score is 57 and the minimal clinically important difference is 5.7 points.', 'timeFrame': 'immediately after the intervention'}
- {'measure': 'Change in Action Research Arm Test', 'description': 'Upper extremity function measure. The measure is a 19-item test divided into four subtests (grasp, grip, pinch and gross movement). For each item, the patient is asked to perform a simple task that involves a functional movement of the affected upper limb. Each task is rated using a 4-point ordinal scale. The maximum possible score is 57 and the minimal clinically important difference is 5.7 points.', 'timeFrame': '3 months after completing the intervention'}

Please estimate the sample size based on the assumption: 
80% power, 5% significance level, and a dropout rate of 15%.
Sample size
        The sample size calculation is based on a clinically relevant difference between treatment groups with 80% power and a 5% significance level. Considering that the minimal detectable change of the ARAT (primary outcome) is 5.7 points and that an acceptable difference between groups of 15% is defined to be clinically meaningful [84, 85], a sample size of 26 participants will be required in each group. From experience gathered in previous studies [32, 77], the dropout rate in this type of interventions is relatively low (15%). Taking this rate into consideration, a final estimation of 60 participants is needed in the study, 30 per group.