The current vogue of taking songs from the American songbook, which has served Tony Bennett, Rod Stewart and Barry Manilow so well in recent years, is nothing new; Bobby Darin was doing it back in 1961.   Love Swings tells the story of a relationship via twelve classic tracks, with the first six (which would have made up the original first side of the album) concerning the joys of being in a relationship and the second six detailing the downside.   It is has been described as the most sophisticated album of Bobby Darin's career and it is hard to disagree.