Another recording of me playing the keyboard:
I recorded the video on my Nexus phone, which I put up on a big tripod. I bought this tripod a few weeks ago at B & H on 34th Street, the largest and coolest electronics store I've ever been to, by a huge margin. Since it's largely staffed by Hasidim, I've memorized its name as Beards & Hats. They have tons of fascinating pro audio and video equipment, including objects that cost more than I make in a year.
There seemed to be hundreds of tripods there and it was fun to figure out how they all work and which one suited me better. I ended up buying this one as well as this phone grip to go with it.
I recorded the audio simultaneously with, but separately from the video by simply passing a cord from the keyboard's audio-out jack to my PC's mic jack and hitting the record button in Audacity. I then used Audacity to sync the low-quality audio file from the phone with the better audio that I recorded directly from the keyboard. Then I combined the audio and the video in MS Movie Maker.
I've noticed that when I try to play better, with more feeling, less automatically, I make more mistakes and my muscles are more tensed up. They get tired more quickly in this mode.
This is a general pattern. I used to draw funny faces as a kid, some like the spinning head in the upper right corner of this page, some in different styles, and I noticed back then that it was physically more tiring to make interesting drawings than boring ones. My arm and my general posture were more tensed up while I was trying to draw well. The same is true with singing. Regardless of one's ability level, doing more aesthetically-valuable work requires one to literally burn more calories than just going through the paces.
Compare that to the typical advice that one gets on this topic from TV: "relax, get loose". All mass media life advice is wrong. Get tense! Drink some coffee beforehand. Be in good physical shape, 'cause you'll need it.