Music is central in most children's lives. Understanding its relevance will advance efficacious pediatric supportive cancer care. Qualitative clinical data-mining uncovered four music therapists' perspectives about music and music therapy's relevance for pediatric oncology patients up to 14 years old. Inductive and comparative thematic analysis was performed on focus group transcripts and qualitative interrater reliability integrated. Music can offer children a safe haven for internalizing a healthy self-image alongside patient identity. Music therapy can calm, relieve distress, promote supportive relationships, enable self-care, and inspire playful creativity, associated with "normalcy" and hope. Preferred music and music therapy should be available in pediatric oncology.