You can see his progress in these videos, he's doing a great job of traveling forward and reaching down. I'm not forcing him into any headset, but I place slightly more rein pressure when his head comes up so it just feels uncomfortable to him and he is rewarded with very light pressure when his head is down. You'll notice that he is distracted easily and that's the four year old brain showing.
I'm trying to keep that forward movement, Calvin has more "whoa than go" so the dressage whip is only used as a secondary cue when he ignores my leg that is asking him to go forward. I don't want to have to squeeze him with my legs every step he takes to remind him that he needs to keep going at this speed, so when he slows down I slightly tap with the whip. If a tap doesn't work, he gets a stronger tap until he listens. You may be wondering, isn't that what spurs are for? No, in Classical Dressage, spurs are only used for higher movements such as lateral work (moving sideways), piaffe, passage, etc. because the spur delivers a pinpointed cue on the belly/sides that is very specific. Using spurs too liberally can dull the horse which creates tension in the riders leg from constantly spurring their horse to respond.
Now, we are throwing transitions into the mix: walk to trot, trot to walk, trot to canter, etc. What is nice is that there are dressage tests for four year olds, so I can kind of see what is expected in a dressage four year old class and model our training after this. This is what a full size dressage arena looks like, there are letters on the outside (visible) and letters on the inside (invisible). So when they say medium trot at A, you're supposed to make your transition right at the A marker. This means your horse has to listen to your cues immediately, but smoothly, easier said than done. One of the other dressage riders mentioned how when her horse was first learning transitions, she called it "doing the Phoebe," which is probably the perfect description. "Friends" fans will likely remember what I'm talking about, but if not here's the clip.
Anyway, we are a work in progress, but stay tuned for more updates :)