"BA BA BA BA BA," Modest Mouse frontman Isaac Brock sings out several times at the start of 'Classy Plastic Lumber,' an infectiously poppy hidden gem on the 'Float On' hitmakers' 2001 album 'Sad Sappy Sucker.' Unlike many hidden tracks, 'Lumber' isn't featured at the end of the album. Instead, it's the fourth track, and because it wasn't listed on the original back sleeve, all of the songs after it are out of order.