Duane has put 36 "piano playing secrets of the pros" into 36 one-hour audio CD's. He explains each technique, then DRILLS you for a solid hour on that technique. You'll play along with him on each technique until you understand each technique and can execute it by yourself. This is HARD WORK, and not for beginners. While it is far better to subscribe to the entire Pro Secrets series, there are some people who would rather purchase them one at a time. These are drill CD's, each an hour long, and they drill you on just one subject. The idea is to spend an hour a day for 30 days on just one technique, and then move on to another technique. Here are the individual CD's. They are $39.00 each: