With Country Act of the Year and Female Vocalist already in hand, Jo Dee Messina was called to the stage for a third time at the recent Kahlua Boston Music Awards — and given the night’s highest honor — Act of the Year. Not only was Messina the first country artist to be nominated for the top award, but she beat out pop, rock and swing sensations Aerosmith, Paula Cole, Mighty Mighty Bosstones and Rob Zombie. “It was awesome,” says the Holliston-born songstress moments after her name was read by Dawson Creek TV star and fellow Bostonian Joshua Jackson. “When you look at all those other artists, and you think about me being a country act … and this being Boston! It was a shock and an amazing feeling.” Messina performed a stripped down “Even God Must Get The Blues,” from her Boston Music and Academy of Country Music nominated Album of the Year I’m Alright. “I dedicated this song to the people of Littleton, Colorado, and the place got so quiet. The vibe was intense.” To celebrate, Messina and her musicians did so in classic Jo Dee style — they ordered a regular crust pizza with mushrooms.