This toddler and tween show the power of song in viral video

Sometimes elder siblings have the best instincts. In a video that has been viewed close to forty million times, Utah mom Amanda Bowman Grey shows her 12-year-old daughter, Lydia, babysitting her toddler, Bo, and keeping him occupied by playing the guitar. Bo, who has Down's syndrome, sings along and is able to pronounce some of the words to "You Are My Sunshine."

The video makes a compelling case for using music and songs to help kids with Down's syndrome develop oral communication skills. "It’s proof that music therapy works," writes Amanda. "Bo is 25 months old and has a 12-word vocabulary. Every word he has learned has been through music and singing." According to Amanda's Facebook posts, the family first played "You Are My Sunshine" to Bo while he was recovering from heart surgery. She writes that since then, "it has become his theme song."

Read more: We're getting all the feels from this music therapist who records babies' heartbeats Helping kids with sensory processing disorder