The Chi-Lites' "Oh Girl" is one of the classic soul ballads of the '70s, and the finest of many classics written by the group's leader, the perpetually broken-hearted Eugene Record. His restrained but aching lead vocal is almost a solo performance (the other three Chi-Lites add only a few wordless harmonies and one line per verse), and his passionate delivery of his own beseeching lyrics is a marvel. (Compare Record's tasteful restraint to the over-emotional wailing on covers by Leo Sayer, Paul Young, and even the usually more aware Smokey Robinson for a quick demonstration of how true soul is not always about keening and melisma.) The arrangement, credited to someone named Tom Tom (probably Record again, who also produced the song and was probably getting shy by his third or fourth solo credit), is magnificently simple, with an almost minimalist string section that adds to the lushness of the vocals without being overbearing, and the brilliant stroke of a wailing harmonica part, a surprisingly down-home touch for such a stylish ballad that's probably the song's crowning achievement. Nearly every cover of the song has swiped the harmonica part wholesale, proof of how key it is to the song's success.