Almost exactly one month ago we had the biggest earthquake Salt Lake City has experienced since the 60's, 5.7 magnitude. It did some serious damage. Luckily our old wooden house seems to have taken it pretty well. There were multiple big aftershocks that same day and in the following days, but things have calmed down with only small imperceptible tremors since then. On Tuesday night around 9:00, I was in the back room wailing away on one of my strats to a Voodoo Chile backing track. I had both the amp and the backing track cranked right up to the threshold of home peacekeeping levels. Suddenly my wife busts in the door and says "I can't believe you didn't feel that!". We'd just had a 4.2 aftershock, the biggest in a month. I said "well this whole room was already shaking, so nah, I didn't feel it at all." She said it was VERY noticeable to her at the other end of the house, it was on the news, lots of people felt it. Cracked me up, I would've never known it even happened if she hadn't come in and told me. Jimi to the rescue! We had another one around 7:30 this morning that registered as a 4.21. I was standing in the dining room with a cup of coffee and I definitely heard, felt, and saw this one. Heard a rumble and the whole house started vibrating rapidly. Pictures on walls and shelves started shaking, my wife's big cpu monitor from work on her makeshift desk started rocking back and forth, went on for about 5 seconds. She and the dog were still in bed upstairs when it hit. After it stopped, they both promptly showed up downstairs.