One of the most important treatises written by the 3rd Karmapa, Rangjung Dorje, and which Kagyu masters teach worldwide, is
The Treatise Distinguishing Consciousness from Wisdom.
This recent commentary by Thrangu Rinpoche was recorded at the 11th Vajra Vidya International Seminar in Sarnath, India, March 8 - 18, 2011.
This is an audio CD in the MP3 format. It should work on all computers and most modern CD players.