Complex sentence: Lyrics have been traced to the 17th Century, are variable, and have passed under various titles, including "The Nightingale" and "The Grenadier and the Lady".
Split into simpler sentences: Lyrics have been traced to the 17th Century. There are a number of textual variants, and the song has a number of titles, including "The Nightingale" and "The Grenadier and the Lady".