NPR program - On the Media - has the following piece.
On August 28, 1963 Martin Luther King Jr. did what he’d done countless times before: he began building a sermon. And in his sermons King relied on improvisation, drawing on sources and references that were limited only by his imagination and memory. It’s a gift — and a tradition — on full display in the “I Have A Dream” speech, but it’s also in conflict with the intellectual property laws that have been strenuously used by his estate since his death. In a segment originally aired in 2011, OTM producer Jamie York speaks with Drew Hansen, Keith Miller, Michael Eric Dyson and Lewis Hyde about King, imagination and the consequences of limiting access to art and ideas.
On the Media page with links to transcripts and streaming version of story.