Since country's earliest days, many of its artists have tried to expand their audience by catering to the mainstream. The Nashville sound of the 1950s and '60s succeeded at this. In the '70s, artists such as Ronnie Milsap and Kenny Rogers perfected the formula, the latter selling millions of records thanks to smooth-edged, virtually twang-less songs including "Daytime Friends," "The Gambler," and "You Decorated My Life." Nashville was enamored with this new sound that strived for worldwide accessibility, and pop artists such as Olivia Newton-John, Debby Boone, Marie Osmond and John Denver began cropping up on country radio stations and winning country music awards. Dolly Parton jumped on the bandwagon too, leaving her traditional country sound behind for a pepped-up and far glitzier persona. Country pop's influence is apparent in many contemporary country artists such as Garth Brooks and Alan Jackson, who meld country pop's glitz with touches of rock and new traditional country songwriting.