"Sweet dreams of you"

These lyrics are from a country ballad called Sweet Dreams, originally recorded in 1956 by Don Gibson, then later by Patsy Cline in 1963 shortly before her death, and again by Reba McEntire in 1979. Constantine is probably listening to McEntire's version, since it was the most recent.

Listen on Spotify:  Don Gibson   Patsy Cline   Reba McEntire