Folk songs had been well-loved during the Ming and Qing dynasties. Numerous popular tunes came into being as a result. Among these tune titles, one often finds cases where a tag-on phrase attached either before or after the title. In this article, I gather data from a wide variety of materials and through analysis, induction, comparison, interpretation and verification I study types of tag-on phrases. I then investigate a few tag-on phrases whose meanings require further examination. Finally, I discuss the influences tag-on phrases on the trend of the development of popular tune titles. My intent is to unravel the complicated and interwoven relations between original tune titles and tag-on phrases. It is hoped that this article will prove helpful to scholars studying folk tune titles.