Doing it right

I'll never, ever suggest that there's a right way to do something. I got out of that habit years ago, when I realized that my way was not necessarily a better alternative to the highway.

When I posted about at what stage one should memorize music, I was probably a little too dismissive of the practice of bringing a piece to playing level before memorizing it. In my previous post, I discussed why I work from scratch when starting the memorization process, and I also gave some tips on memorizing a piece once its already "in the fingers."

But what are the advantages of doing what I advise against? That is, what are the advantages of

It might look like an advantage. Is it?

bringing a piece to playing level and then memorizing it? That seems to be what a lot of musicians are doing, so it can't be so bad, right?

Tactile Advantage
The piece is in your fingers, now you just have to commit it to memory.
Aural Advantage
You've played the piece a lot from score--so much that you've brought it to performance level. Now it's in your ears!
Visual Advantage
You've seen the score so many times that you've been able to solidify tactile and aural memory. It shouldn't be hard to visualize the score away from the instrument.

Wow! These are really strong advantages, and, as a write this, I'm wondering if I should take up this method. 

Not so fast!

Look at my previous post...carefully. Presuming you take my advice to heart, you'll see that the process of "learning" a piece and then memorizing it becomes a two-step process. You've taken a lot of time to get a piece up to playing level, and now you have to go back to a crawl in order to bring it to a non-tactile-based memory level. And, unfortunately, your foundation will always be one of tactile memory since that's what sticks before aural and visual memory become certain.

In the end, it may seem that the "play first" method is faster. But, aside from it being a two-step process, it also has the potential of creating an insecure foundation in tactile memory. Just as correcting wrong notes is very difficult when you've already learned them as right notes, undoing tactile memory to create an aural/intellectual foundation will take much time. And even once you're good to go, you may still have concern about your shaky starting foundation.
Take it from one who knows. Practice patience.