Marching boldly into my latest installment of “Boston Bands This Week”. We start with “a classic”, Mary Lou Lord, whom I must be recalling from the early 90s when I first moved to Boston. She’s doing a special acoustic performance on Wednesday at Arts at the Armory in Somerville, which will probably sell out if it hasn’t already. Then there’s a few very cool bands playing at P.A.’s Lounge on Friday, including a personal favorite, the wacky and wonderful John Powhida International Airport. Finally on Saturday, there’s a CD release party for someone who just recently came to my attention, Somerville-based singer-songwriter Danielle Doyle, who’s joined, once again, by some cool local bands – this time, in the acoustic, ambient, and Americana vein.