Original: The Nightingale (Luscinia megarhynchos), also known as Rufous  and Common Nightingale, is a small passerine bird that was formerly classed as a member of the thrush family Turdidae, but is now more generally considered to be an Old World flycatcher, Muscicapidae.
Simplified: It used to be classed as a member of the Thrush family Turdidae.