"So Long, Dad"

I was thinking about "So Long, Dad" yester-day and discovered an ambiguity in the lyrics.  One line could be written as either "Just drop by when it's convenient to" or "Just drop by when it's convenient, too."  The meaning isn't affected very much because in either rendering, "to[o]" isn't essential and really just sets up the rhyme for the following line, which Manfred draws particular attention to in an interview on Live at the BBC 66-69:  "Be sure to call before you do."

"To" is actually sort of redundant since it merely indicates an ellipsis of the repeated verb:  "Just drop by when it's convenient to [drop by]."