The power of — a doc.

Michael J. Fox famously rocked out on guitar to Chuck Berry’s “Johnny B. Goode” in an iconic scene from “Back to the Future.”

But now it’s more like “Johnny B. Gone”: The instrument Fox’s Marty McFly played at the Enchantment Under the Sea high school dance has been missing for nearly 40 years.

Now, as the 1985 blockbuster turns 40 on July 3, the search for the cherry red Gibson ES-345 guitar is being tracked in an upcoming documentary, “Lost to the Future.” 4

Gibson Guitars, Universal Home Entertainment and filmmaker Doc Crotzer have teamed up for the search for the long-lost axe.

The hunt was launched on Tuesday with a video featuring Fox and his “fellow “Back to the Future” cast members including Lea Thompson, Christopher Lloyd , Harry Waters Jr. and

See Full Page