Live Nation is once again offering $20 “all-in” (aka service fees included) tickets to over 2000 shows happening this summer with a promotion they’re calling National Concert Week. Those shows include concerts with such artists as  Ms. Lauryn Hill, Janet Jackson, Steely Dan/Doobie Brothers, Arcade Fire, Beck, Dead & Company, Paramore,  Bon Jovi, The Smashing Pumpkins, Counting Crows/Live, Weezer/Pixies, Dwight Yoakam/Lucinda Williams,  Alan Jackson, Bush/Stone Temple…