Piper Event, of Howle Hill, Ross-on-Wye, and Mr Piper, 47, of Wye Street, Ross-on-Wye, were both accused of one count of contravening health and safety regulations by exposing workers to risk.
Piper Event Services Limited, of Howle Hill, Ross-on-Wye, Herefordshire, and company director, Mr Piper, 47, of Wye Street, Ross-on-Wye, are both accused of one count of contravening health and safety regulations.
Past performers, who are never announced until they take the stage, have included Diana Ross, John Mellencamp, Sheryl Crow, Faith Hill, Lionel Richie, Jon Bon Jovi, Paul Simon, Stevie Wonder and Elton John.