WOKY (AM 920), which has been playing Top 40 hits from the 1960's and `70's, undergoes a format change at 6 a.m. Thursday. The station will be known as "AM 920 The Wolf," a classic country operation featuring artists like Johnny Cash, Merle Haggard, Patsy Cline, Loretta Lynn, George Jones, Dolly Parton, Waylon Jennings, Willie Nelson and 1980s artists like Anne Murray, Ronnie Milsap and the Oak Ridge Boys.