[jb1991]

Sorry, I'm just unconvinced. There is no doubt that learning, for example, a Chopin Etude with the busiest hand alone is going to be a natural step before adding the second hand. Think about the reverse, would you expect someone who can play both hands together well to also be able to play them separately? Muscle memory does not disappear just because you add a second hand. The coordination does have some differences, but it's hardly a totally separated phenomenon.

[Hackbraten]

> There is no doubt that learning, for example, a Chopin Etude with the busiest hand alone is going to be a natural step before adding the second hand.

To me, the phrases “There is no doubt that” and “natural” come across as if a certain amount of debate might be warranted.

> would you expect someone who can play both hands together well to also be able to play them separately?

Some may be able to, some not so easily. Think of a Bach fugue whose middle voice sometimes alternates across both hands. I’d say it heavily depends on the player and the piece.

> Muscle memory does not disappear just because you add a second hand.

Good point. I think my choice of words was poor when I claimed muscle memory would reset. What I do claim is that some people, myself included, experience friction in their muscle memory when they move between practicing both hands and a single hand.

[jb1991]

> Think of a Bach fugue whose middle voice sometimes alternates across both hands. I’d say it heavily depends on the player and the piece.

It's ironic as I was actually thinking of my own experiences learning Bach fugues and how, when I learned the hands separately, it seemed to help a lot. Especially since finger technique with Bach is so technical and how you choose your fingering is critical, it's hard to master that for both hands simultaneously. After all, you are still using the same fingers when you add the two hands together, so giving yourself a chance to focus on just one hand seemed to always help me a lot -- not just help me, but actually was a requirement to getting it learned. I don't think I could have ever learned some of those intricate fugues if I'd done both hands together. Or at least, it would have taken longer. For example, which is easier, sight reading music with both hands, or sight reading each hand separately?

[Hackbraten]

> For example, which is easier, sight reading music with both hands, or sight reading each hand separately?

That highly depends on the performer and the musical properties of the work.

Sight reading a single voice can be harder than with both hands because the voice of one hand may not always give you a complete picture: what the tonal center and functions are, how a theme or sequence develops, and how the voices relate to each other.

[jb1991]

I mean, from a technical level, it’s hard to argue that playing a single voice, or single hand, requires less effort than sight reading multiple voices or two hands simultaneously.

[Hackbraten]

From a technical level, you’re obviously right.

But when sight reading, there’s a lot more going on than just technical skill. Depending on the person who is sight reading and which piece, playing both voices at the same time can, on an intellectual level, help tremendously with comprehension that it more than offsets the additional technical burden.