The first Ovation electric-acoustic guitar appeared in the late-'60s after the closing of Charles Kaman’s helicopter design firm. Borrowing from his blade designs, Kamen built innovative guitars with rounded composite plastic backs and Sitka spruce tops. These synthetic backs and patented electronics earned Ovation a reputation as one of the most innovative guitar makers in the world. Endorsed by Glen Gampbell and later Robert Fripp and Melissa Ethridge, Ovations like the Legand, AX, Elite, and Adamas Series are acoustics made for active performers.