This is a question I have heard from many parents of children with special needs who are receiving music therapy.
If you think about it, it's actually a compliment.
They bring their child to you. They watch as their child achieves goals and learns so much with this nonthreatening medium called music. They observe and see that the music therapy interventions are motivating and fun, and these interventions allow their child to succeed on so many different levels.
How can they tap into all of that at home?
You can't exactly carbon copy each music therapy session, nor can you expect the child to respond the same way every time. You can recommend styles of music or certain standard children's songs/CDs,etc. that the parents can purchase and use with their child. You can also share particular songs you are using in sessions that their child particularly responds to each session.
I think parents need to think outside of the box in order to be really successful helping their child at home. I think a good start is to have a small assortment of rhythm instruments available to their child in their home (these can be homemade as well) and the parent can allow their child to initiate music time in their home. It is very helpful if parents are aware of their own child's goals beforehand, so that they can create fun experiences on the spot that help target those goals.
An example for this would be something like learning left and right.
Maybe the child gets out his drum and starts banging away with his right hand. The caregiver can instantly join in with a drum or just sit in front of the child and clap along while chanting something very simple like, "Playing with your right. Playing with your right. Playing drum with your right hand and that's alright."
Then the parent can encourage the child to switch hands and change the chant to, "Playing with your left. Playing with your left. Playing drum with your left hand and it's the best."
Keeping it fun and simple is really the key. Children love music and they love interacting with people with music.
How do you encourage parents to help their children at home?