This week on How I Met Your Mother, Barney, Ted, and two versions of their future selves harmonized a rendition of Billy Joel’s “The Longest Time.†The last three months have seen a wave of “Piano Man†references: Joel has been the subject of a tribute on Smash and a sketch on Kroll Show, and his record label has released yet another compilation, She’s Got a Way: Love Songs. Each celebrates (or teases) his classic work, because at this point, that’s all there is to address: This year marks the twentieth anniversary of his last original pop album, 1993’s River of Dreams, and he shows no signs of ever making another. At this point, the non-Joel-obsessed masses out there are probably pretty tired of his biggest hits, and a casual fan from long ago has finally reached his or her breaking point with Joel’s karaoke staples. However, these people should know that although he has barely put out anything new in twenty years, Joel has plenty of past material that isn’t played to death and will still feel new. Herewith, twenty noteworthy, infrequently played tracks that you won’t find on any of his three greatest-hits volumes. At least one is plucked from every one of his albums, from his debut, 1971’s Cold Spring Harbor, through River of Dreams.