A video is a video! He didn't say here is a video of me singing live, playing the piano - it's a nice video of a nice song that sound pretty good. It's like claiming that your final after all the faffing around was done direct to stereo. I suspect the mics were simply put in the viewfinder as eye candy. You cannot dissect a recording from a lip-sync video, so whatever mics you see are pointless to the audio product as heard.
A few corrections. Although you can alter MIDI velocity in the editor, your brain would explode from trying to do this from mouse or step entered sequencing. The facts are that by listening we know he is a sympathetic pianist rather than a precise one - in the track you can clearly hear octave left hands but in the video he rarely does it with the force the recording shows - his left hand is busy, but different to the video, and sometimes his right hand is playing close chords that you cannot hear, so it may or may not be the piano we are hearing.
I make a reasonable chunk of my income from recording pianos- specialist music and to be honest a bit boring, but the classical pianist I work with has a Yamaha C series in his home - but it took a lot of effort to make it sound nice in the quite boxy, hard walled room - so much so that the sessions were very long, and errors increased. I ended up using a combination of close miking plus a stereo mic in the curve. I've got a couple of VSTi pianos and one is the piantoteq. This actually responds well to clever pedaling - half pedals and pedal twiddling actually work. The extra pianos are also well worth getting. In the end we found a very realistic program, that worked for us, and we moved away from recording his real piano altogether. He records on a quality 88 note weighted keyboard that is close to what he feels is right, but the benefit is that I can simply repair the odd duff note in a long piece, and even steal little bits from other places. Sure, it's cheating, but so what? One or two of the CDs have a mix of recording methods, and although I know which is which when I look it up, they don't stand out.
What I do know is that just because you have a nice piano available, it doesn't guarantee a good recording, no matter what mics you have available. The key, as ever, is experiment. No two pianos are identical. I do not subscribe to any notion of X mic is always rubbish, while Y is always good. I'd happily record with a Samson, if it worked for me. I really don't care what the price is - it's unimportant, the sound is paramount. Far, far too much snob value on mics - the only thing I ever avoid are USB mics - a few sound ok and have gain controls, but the problem is that few recording systems can record from two digital sources at the same time, so you have to mess around with system settings and I hate that.
I don't use audacity myself, although I do have it on the computers, and use Cubase 8 and Sony Sound Forge by choice for recording and editing - I have adobe Audition with the rest of the pay monthly package but don't like it much - however I have never found any of them sound different from the others. It records and manipulates digits - all my digital recorders that come after the A/D sound the same, and I've never even considered Audacity to be flawed in this way - no idea where this came from? Audacity was, as far as I know, designed to be a pretty complex audio recorder and editor. I've not discovered any audio anomalies - perhaps I will go and have a play?
The guy who made the video, assuming it's the same person who sang and played did a damn good job - but please, let's not over analyse the video.
