The author describes some of the processes required in creating Experiments in Musical Intelligence, a computer program for the simulation of musical styles. He then outlines many of the problems listeners face when attempting to deal with successful output from such programs. These problems involve redefining terms, debating humanversus computer-creativity and, ultimately, grappling with the meaning of music. This discussion includes an example from the computer-composed opera Mahler. The author argues that such music should be considered integral to mainstream humancomposed music since it results from a collaboration between humans and the machines they have created.