If you don’t pay attention to those pesky lyrics, Weezer’s first new song in three years, “Back to the Shack,” which they debuted aboard last week’s Weezer Cruise, is as good as anything they’ve released in a decade. The hook is killer, and Rivers rips out a nice solo. But when you hear the words, you remember, the band is now basically season four of Community. They’re self-referential and wink at you and oh god I miss “Why Bother?”