There’s music, merchants and more afoot coming soon to the stages of the Crescent City, with a touch of the circus, a bit of rouge and a lot of interesting entertainment. Country music, including a new number by one of the famous Williams family of troubadours, becomes the backdrop for the excitement and entertainment audiences have come to expect from Cirque du Soleil in the company’s new “Songblazers: A Journey Into Country Music” show to soar through the Saenger Theatre for four productions this weekend.