Amy Grant and Michael W. Smith @ Celebrity Theatre

Amy Grant and Michael W. Smith go way, way back — but not in the way you probably think. Amy Grant, probably the most important Christian pop musician ever (even if that might not be the most impressive accolade) gave Smith his big break, hiring him to play keyboards on her early-’80s tours. Since then, he and Grant have made successful yet temporary runs at mainstream pop stardom. There’s really no reason to be interested in this show if you don’t have a history with either artist, and there’s a chance that this “2 Friends” tour reuniting Grant and Smith might disappoint the large number of their fans who have lost track of Christian music in the past decade or so. Amy Grant once represented a clean, young, attractive, and optimistic ideal for young women and a non-threatening sexual object for men. Michael W. Smith was a little more nerdy, rocking a deeply argyle style for one album, but he made great music for hand-holding and sing-alongs at camp. Couples skate at Christian night at the rink in 1991? You know “Place in This World” was playing. Now, they may be playing mostly their recent largely terrible stuff, which would be a downer, but when Grant and Smith duet on “Friends,” it’ll be like the last two decades never happened.