Mattie J. T. Stepanek, whose poems formed the basis of Billy Gilman’s third album, died Tuesday (June 22) in a Washington, D.C., hospital from complications of mitochondrial myopathy, a form of muscular dystrophy that afflicted him throughout his short life. He was 13. The power of his poems (which he began writing when he was 3) led singer Billy Gilman to record a collection of them. The resulting album, Music Through Heartsongs: Songs Based on the Poems of Mattie J. T. Stepanek, was released in April 2003. Several prominent Nashville songwriters provided music for the poems, including Richard Leigh, Tom Douglas, James Slater and David Malloy, who also produced the album.