The full sheet music for the ballad version of this song is in a compilation album called "101 Most Popular Songs of the Rock Era" on page 234. It is available on Amazon.

WARNING NOTE: There are several editions of the this sheet music compilation album and some DO NOT have this particular song in them. You need the Catalogue # VF1523 version (not the VF1959A version). Check with any seller that the song is in the version being sold before purchasing.

The song is in the Key of F all the way through. Although there are some different chord changes, there is no modulation written into the sheet music in this album