A great audio interview with L. Randall Wray by Tom O’Brien on money and monetary theory.
There is some excellent discussion of the origin of money and the theories of G. F. Knapp, and, towards the end, analysis of the oil market speculation from 2004 to 2008.
N.B. when checking this post I noticed the embedded audio did not seem to show up. Please leave comments if it is not working.