Sunday, October 4, 2009


I was excited by the title of a recent post on the Dallas Steinway blog: The Importance of Good Action on Pianos. I guess I was expecting a technical article about the motion and interaction of elements of a piano's action and how they affect playing. But the article seems more aimed at piano buyers, with the message: "don't be put off by a firm action... it's good for you".

The reason for my excitement (and disappointment) is that I spend a lot of time thinking about how pianos sound and feel. And I think there's more to action from a player's point of view than just "firm or not firm". So why not write about it on my blog?

When a piano requires relatively more energy to play, people often describe its action using words like "heavy", "stiff", "firm", etc. But I've played lots of pianos that felt "heavy but loose", or "light but stiff", suggesting there's more than one dimension. So here are the elements I think of when describing a piano's action:
  1. Weight (heavy vs. light)
  2. Stiffness (stiff vs. fluid)
  3. Tightness (tight vs. loose)
  4. Response (responsive vs. sluggish)
These may or may not map simply to physical differences in the machinery of the action. And they're all closely related to the subjective perception of how effort produces sound. I think of this effort-in-to-sound-out as a kind of Transfer Function, which I'll describe in another post. For now, I'll say a little more on each of the four elements.

I see weight as a perception of how much matter it feels like you're moving when you press a key. This may correspond to the actual weight of the moving pieces. It may also be affected by a sense of inertia (how much effort it takes to get things moving, and how much it feels like they keep moving once in motion).

Stiffness to me seems more similar to friction. How fluid is the motion of the key? The action can be stiff but light (like pushing an empty cardboard box across a table), or heavy but fluid (like pushing a heavy stone across ice).

The tightness of an action is more about the amount of extraneous motion. The motion can be lateral (for example, extraneous side-to-side motion if the guide pin is too loose in the bushing) or vertical. Two kinds of vertical looseness are excessive bounce on key-up and excessive mushiness at the bottom of the key bed. It's easy to imagine an action being heavy or light and loose, and fluid and loose. I'm not sure I can imagine stiff and loose.

For me, the response of an action is about the perceived directness of the connection between motion and sound. More than the other elements, response seems temporal to me. Is there a feeling of delay in the action? How quickly are notes available for repetition? Does the key motion seem synched with the note sounding (especially when playing softly)? Informally, does the piano do what you want it to without hesitation?

So where do various pianos stand on the four dimensions? I'd say the action on my piano (an Essex 183) is medium-weight, somewhat stiff, nice and tight, and extremely responsive. The Steinway D I played at my last recital was fairly heavy, but fluid and a little loose, making it feel overall a little sloppy to me (the lack of stiffness and tightness failing to hold the inertia of the heavy action in check).

Of course, all of these perceptions are in the context of how the piano produces sound in response to force exerted, which is the topic of my next post.

1 comment:

  1. I'm going to go and see where my piano stands on all these dimensions. I haven't really thought very much about it. It just feels good to me.