The goal of this clinical trial is to learn how community-based music mindfulness interventions impact anxiety, depression, and overall emotional well-being in children and adolescents with attention-deficit/hyperactivity disorder and/or anxiety. The main questions it aims to answer are:

• How do participants' psychological states change from the start to the end of the intervention?
• What physiological changes, including heart rate variability and sleep patterns, are observed after the intervention?
• Is this study feasible and acceptable to the community?

Participants will:

• Attend in-person sessions, bi-weekly for 8 weeks
• Regularly complete psychometric assessments
• Wear fitness trackers daily, including overnight, throughout the study period
• Track self-guided intervention online
• Participate in semi-structured interviews pre-/post-study

Inclusion Criteria:

• Ages: 8-12

Exclusion Criteria:

• Regular mindfulness or meditation practice (at least once/week)
• Participation in formal meditation or mindfulness interventions within the past year
• Suicidal ideation, self-injurious behaviour, or homicidal ideation
• Active psychosis symptoms
• Hospitalization within the past 6 months for psychiatric or medical conditions
• Diagnosis of seizure disorder or other neurological disorders
• History of thyroid or cardiovascular diseases
• Current substance use disorders

De-identified data will be shared in aggregate through pre-prints, publications, and community stakeholders.