Puzzle 4 (expert): “Both Sides Now”

Here's the expert version of contest puzzle #4. Solve using the Crossword Compiler applet below, download a PDF, or use Across Lite.
The meta is a hit song from the 1970s.
Submit your answer to the meta using the form on the home page.

Both Sides Now (expert) by Pete Muller

The deadline to submit an answer has passed. The solution will be posted Tuesday August 14.