From the moment they appeared bare-shouldered on their 1976 debut, “Dreamboat Annie,” Heart's Ann and Nancy Wilson made the point to show they were going to be different from the time's established female songwriters. Responsible for such well-known singles as “Crazy on You,” “What About Love” and “Barracuda,” the two sisters took the influence of Led Zeppelin and turned it into their own visceral arena rock, becoming one of the biggest musical acts of the 1980s. With big hooks and an unabashedly loud sound, the ladies of Heart are scheduled to perform at Innsbrook Pavilion on Wednesday, Aug. 11, at 6 p.m. $20-$25. 423-1775.