that's yo-yo ma playing a piece by the great johann sebastian bach.kers on the front lines. he said their dedicated service gives them hope. this is his second video he shared of himself playing what he calls songs of comfort as the coronavirus spread. he's not the only one using music to brighten people's lives. did you tell joins us again from his new york apartment to play the guitar for us. vlad? >> don't get me started, gayle. don't get me started. >> that was an ad lib. >> good to see you once again. taran and calliope tien are 9 and 6 years old. just like yo-yo ma, they play the cello. after their mom rebecca checked in on a self-quarantined neighbor she made other plans. >> hello, hello. >> dressed in concert clothes and aide by mom, siblings taran and calliope tien are here to perform for their self-quarantined neighbor. >> two, three, four. ♪ >> 78-year-old helena schlam. >> i haven't been out of the house well except in the yard for the last five days. >> she lives alone and says she got a call from rebecca asking if she needed groceries. w