For some couples, a look says it all. Others need but a few simple words. Anna Kendrick and James Corden, cycling through an entire relationship on Wednesday’s Late Late Show, pulled from the whole catalogue of love songs to produce a pop opera of fuzzy feelings. From “Can’t Feel My Face†to “Marry You,†Kendrick and Corden made the song of their heart the song of our ears. Kendrick and Corden sitting in a tree, s-i-n-g-i-n-g.