Earlier today Guitar World posted a short interview with Alex Lifeson where he discusses the writing of Closer to the Heart:

"All of our early albums were written on acoustic guitar. When Geddy [Lee, bass and vocals] and I would write the music, we'd sit down with a cassette recorder and two acoustic guitars, in spite of the fact that we were a hard rock band.

"'Closer to the Heart' is a sweet, ballady type of song, but we mix it up. It takes an interesting course as the arrangement builds. Once we got the basic arrangement down, we knew that the intro would be acoustic, and then we took it up a notch dynamically and brought the whole band in.

"The 12-string intro gives it the illusion of being an acoustic piece, and then the rhythm section comes in and the song changes into a kickin' rock tune."

Thanks to RushFanForever for the heads up.