If you’re a follower of Nashville rock, chances are you know Kim Collins. She’s fronted or co-fronted several notable local bands including Kim’s Fable, Pale Blue Dot and most recently, Smoking Flowers, where her captivating, otherworldly vocals complement husband Scott Collins’ earthy, rough-hewn tenor. (Together, the Collinses are arguably the Nashville music scene’s best-looking and most warmhearted couple, two designations that rarely go hand in hand.) News that Kim had been diagnosed with breast cancer stunned her friends and family, as she always led a consciously healthy lifestyle. But as far too many people know, the disease doesn’t play favorites. After successful surgery, Kim’s prognosis is good, but the medical bills have piled up, so her peeps have organized a benefit of epic proportions, including rare performances and reunions from some of the area’s favorite bands of the past couple of decades: Bare Jr., Fleming and John, Human Radio and Joe, Marc’s Brother. And the rest of the acts ain’t exactly slouches — Will Hoge, David Mead, Daniel Tashian and Judson Spence. If you spent a lot of time at local clubs in the late ’90s and early Aughts, this benefit at Mercy Lounge will be like Old Home Week — Kim worked at 12th & Porter for years, and most of those bands were fixtures there.