It is 20 years this week since the school shooting at Columbine, Colorado, where two senior students murdered ten others and a teacher in an unexplained gun rampage.
In the immediate aftermath, local composer Frank Ticheli was asked to write a piece of music for the school band.
He called it American Elegy. It has been performed more than 10,000 times, according to the publisher.
And still the shootings continue.
In this radio feature, Ticheli talks about the process of healing through music.