A PA32R pilot reported his engine lost power so he landed in a cornfield.

Narrative

I departed on an instrument flight plan; 6;000 FT with myself and my two sons on a college tour. After encountering strong headwinds; I asked and received descent to 4;000 FT. My engine suddenly became about 4 times louder than normal. I had full power. I did an instrument scan and I had oil pressure; fuel pressure; oil temp normal; and EGT/CHT scan on all six cylinders appeared normal. I called ATC and said I had engine problems and asked for vectors to nearest airport. They gave me a left turn to [a nearby airport]. I saw some other airports on my GPS that appeared closer and inquired about them but after some back and forth; I continued to [ATC suggested field]. I asked Controller for identifier to put it in my GPS; but didn't get the identifier. Controller then started to say other things. I interrupted and harshly demanded that he gave me the identifier again. At that point; the engine started to vibrate significantly and power started to decline. I looked at mountains between me and [the airport] and then around me and saw a cornfield nearby. With engine slowing; I told ATC I was going to put it down in a corn field. My sons tell me the prop froze on downwind but I don't recall it; but do recall seeing vacuum; low oil pressure; and alternator idiot lights coming on as I was turning base. Upon landing successfully with no damage to airframe; I called ATC and informed them on radio I was down safely without incident to aircraft or passengers. An aircraft relayed the message. Two good Samaritans stopped immediately and contacted park service. I spoke to FAA FSDO and to a supervisor. I checked engine and all appeared intact; engine was seized with no play in prop and oil had 9 quarts. I had 25-30 gallons of fuel. Everyone seemed pleased that I had landed the aircraft with no damage to craft or passengers.