Robert's beautiful performance of Two-part Inventions encouraged me to try to play one. I'm very uncertain about interpretation (dynamics, legato, staccato, etc.) of Bach inverntions.

Was this recorded with a piano or a keyboard?

Sheesh ! You take this even faster than I do, and that is probably already much too fast.
It gets sloppy because of this pace, and that is unnecessary. Poise is everything in Bach. Never hurry, not even when you play fast (does that make sense at all ?).

One thing bothers me here and that is your tendency to play a group of 2 notes somewhat like the first and third note of a triplet, or something in between that. I noticed that a little in some of your rags, where it has a certain charm (though it may not be intended). Of course in Bach this is a sin, and in this Invention it gets irritating, especially near the end where it seems to worsen. My guess is you are not aware you are doing it, but you really need to take care of that. Unless you want Bach to sound like it was sung by the Swingle Singers (for those of you who remember the seventies, or were they the eighties ?)

I agree with Chris here. You must concentrate on playing much more even or it will sound like a horse in gallop. But if you would succeed, I would not mind this rather fast tempo. If you want to listen to something really fast, listen to Gould. He is done in 0:44 and slowing in a lot at the end, of course with perfect control.

Thanks for the advice. I sometimes notice that I accidentally play two notes which should be even like they were the first and third note of a triple. In Jopline I believe that is okey, but definitely not in Bach. Sorry. I'm going to have to pay more attention to that.

As for tempo, it seems that almost every time I hear it played publicly it is much faster than the tempo I play it. This is one of the reasons I am uneasy playing Bach for anyone. I don't know what is correct. I have had much conflicting information, for dear ol' Johann didn't leave us much information.

We never quite know what is correct in Bach - although it is usually clear what is NOT correct
As far as tempo goes, what feels right and sounds right is probably correct. Bach's music can stand a lot of different interpretations.

Should the piano try to imitate the clavier or harpsichord or organ when playing Bach. What about ritardando, rallentando, crescendo, etc.? Terraced dynamics? Very confusing to me.

Isn't it just ! And the worst is you must make up your own mind about it as there os no absolute right or wrong.

Luckily these days a pianist need not make excuses to play Bach on a piano, and is not required (praise be) to imitate a harpsichord or organ. Although it can make sense to do so in certain pieces, depending on the tempo and character. In other pieces, you may want to imitate a baroque trio or other ensemble, and in others, well you can just be glad you are a pianist, and make the most of that. How Bach would have reveled in the sound and possibilities of a modern grand ! I am 100% sure he would not have given the harpsichord a second glance. Not a very good argument of course... and pure speculation. Like some say that had Bach lived now, he'd be the greatest jazz musician ever (yeah I can just see him stompin' away on a saxophone )

Dynamics and tempo variations are all allowed in Bach, I think, as long as they are applied very discreetly. Any excess in Bach will be frowned upon. As I see him, he had the most orderly amd serene mind of all mankind, and that needs to shine through in any performance. About using pedal, that is always a hot issue. I like to use dash of pedal now and then, sometimes to aid the sound, sometimes to create a legato which is otherwise difficult to achieve. But great care must be taken with that because it alwas need to sound clear and calm.

On one interpretative end we have Glenn Gould, like a noisy Swiss clockwork, all the springs and cogs audibly clicking away, harshly exposed under bright fluoresent light. Many people love it. And on the other end there is Sviatoslav Richter with his burnished Russian tone, applying all romantic devices and taking Schubertian slow tempi. Somewhere in between, I guess, lies the truth... now only to find it

sounds very clear to me and I suppose to say need to slow down a bit like myself.
. The piano sounds quite good, is that a yamaha c1 grand If I am not wrong. I can hear the bass is less than c2 so as c3.