Teenage Fanclub’s musical principles are decidedly middle-aged by now, but the Scottish band is still perfectly named. The objective of their fandom (Big Star, Neil Young) is youthful enthusiasm, addressing grown-up concerns with forever-young pop-rock stylings. Bless their Glaswegian hearts, they never sound bitter, 15-plus years after their brief alt-rock moment. Shadows opens with “Sometimes I Don’t Need to Believe in Anything,” and it’s the most unjaded paean to world-weariness that you’ll ever hear. Proof that youth is a state of mind you need never outgrow.