Keyboard covers protect instruments from dust, moisture, and accidental spills. Early pianos had fabric covers, while modern designs use stretchable, fitted materials. Top options include On-Stage (KDA7088 Cover), Gator (Stretchy Keyboard Cover), Yamaha (Key Dust Cover), and Casio (Custom Covers). These covers help maintain key action and prevent debris buildup, essential for home, studio, and stage environments.