What is meant by songs that are "oldies but goodies"?

With respect to songs, "oldies but goodies" is an expression used to describe songs that are old but are still good, especially the ones that are still popular and enjoyable in the current age.

"Oldies but goodies" is applicable to all old songs that are good, but according to Barbara Jastrab, it is used to refer to songs, mainly rock 'n roll, from the late 1950s, the 1960s and the early 1970s. "All Day And All Of The Night," "Like a Rolling Stone," "You've Lost that Lovin' Feelin'," "Where Did Our Love Go," and "I Want To Hold Your Hand" are some good examples of oldies but goodies.