Getting the rhythm is key to good skiing

George and Ira Gershwin must have been terrific skiers. Anybody who's ''got rhythm'' has got a lot when it comes to skiing. Balance is nice - and crucial - but fluidity is what makes it all work. And moving fluidly through the snow, as skis are designed to do, is just about impossible without rhythm.

Recently, my wife had the benefit of a ski lesson, and the instructor was working on easing that major hang-up of the intermediates of the world: a static body position. Skiers want a quiet upper body, but ''quiet'' isn't ''static.'' This particular instructor was working on up-and-down movements on the turns, not so much for unweighting purposes, but to communicate that feeling of fluidity. Interestingly, it's hard, if not impossible, to move the knees, feet, ankles, and hips fluidly and rhythmically if the upper body is twisting back and forth across the fall line.

The difficult thing to accept is that a ski and its skier should almost never stop turning. Even a long, arcing giant-slalom type of turn should be thought of as the beginning of the next turn. And the next . . . and the next. . . .

Mitzi took some notes after her lesson; here are a few of them: ''Slow turns with complete curve. Count 'one, two' on each turn. Keep the count even. Try 'one, two, three.' (Some like ''slow, slow, cha-cha-cha'').''

Use whatever imagery works for you, if it helps you get the rhythm.