The Law of Diminishing Returns

It's taken this a while to sink in. Zara Lawler notes it in The 30-minute Rule on her blog:

I find that anything longer than 30 minutes starts to yield diminishing returns—my mind wanders and my sound gets bad, usually around the 32-minute mark. I know that sounds comically precise, but I’ve been keeping track of these things in my handy practice notebook for years, so I know! In fact, every once in a while I break the 30 minute rule when I’m feeling desperate to learn a lot of music, and it ALWAYS yields the same things: more frustration and a bad sound.

And I brought it up in my comment:

Lately, what I’ve been trying to learn is to STOP when I hit that point of diminishing returns, even if I hit it before the 30 minutes are up.

There are times when I just can't seem to do anything right while practicing a particular piece or section of a piece. My fingering falls apart, my embouchure goes out the window, I fumble measures I played perfectly the day before, or all of the above. My first instinct is to keep working on the particular passage to "get it right." Following that instinct only makes things worse, until I get so frustrated I just want to throw my flute across the room. And it can even set me back in terms of being able to play that particular piece.

Instead, I've learned to do the following: Take a deep breath, put the piece of music aside and work on something else. Or, if I've been practicing for a while, I take a break and come back to something else. Occasionally, it's not the particular piece of music but just playing in general. Then I take a break and come back to it later. If I'm still having trouble, I put the flute away.

Probably something I ought to think about when things frustrate me in other areas of my life.