[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.