Begin sitting on the piano bench only about the front edge or half of the bench, feet resting on the floor, and your knees lower than your hips. This form keeps pressure off of your lower back when you are sitting tall with shoulders back. If your legs dangle, use a footstool.
You should be comfortable enough to lean left and right and toward the piano to play high and low notes or push the piano to create a very loud sound all without having to fall off the bench! Because a young learner does not often require to lean into the piano or left or right, phone books are adequate to rest the feet. Once, however, the pianist is constantly using the phone books to lean, they will slide and become a distraction or a nuisance. I recommend a footstool.
Elbows should be comfortably hanging from shoulders. Wrists are straight enough to balance a Magic Tree House paperback. If the keyboard is too high, a learning pianist might tense her shoulders to keep her wrists straight or drop her shoulders but lean on the piano’s edge with her wrists. Neither of these compensate for good form. I recommend interlocking foam floor tiles (children’s gym mats) because they do not slip when stacked and do not squish like pillows do. When the forearms are parallel to the floor, you have reached proper height.
If you do not have a piano bench, a normal chair works fine. Be careful not to become too comfortable in your chair and be tempted to lean back. Office chairs are not recommended as they lean with the weight and roll along the floor, becoming a play toy instead of a learning place.
Keep in mind that your posture changes with the time of day, depending on how stressed or fatigued you are. If you are still growing, your proportions will certainly change along with your height. Always begin sitting at the piano by checking your muscle tension and comfort. Piano playing is a performance art, so always try to look good!
