So, I brought Calvin in, brushed him and tacked up. He was very good in the cross ties, but I did some work on him letting go in his neck while he was standing there. He needs to start stretching down and forward earlier in his sessions.
I tacked up and got on and he was a perfect angel for mounting. He was very stuck in walk at first, though. Putting a leg on only produced a tighter back and shorter step. We did a lot of walk warm up with only marginal results, so I moved on to trot (which was better) and then a whole lot of canter wherein he started to let go in his back.
Then we did some more trot work and walk work, which was much improved! Very good.