Victoria Nodiff-Netanel carries a 32-key piano everywhere, including hospitals, schools, police stations and parties. But it’s not for her to play.

She has trained her nine miniature horses to run their muzzles along the keyboard, creating tunes that are as tumultuous as they are amusing. Music is one way the mares, part of Nodiff-Netanel’s nonprofit called Mini Therapy Horses, comfort people, especially hospital patients, in Southern California.