The `Pirates of the Caribbean: On Stranger Tides` actor - who has previously played guitar on tracks by Oasis and Shane McGowan - has struck up a friendship with the Aerosmith rocker and says their collaboration is a "dream come true".
He told US TV show `Extra`: "We`ve been hanging out here and there. He`s someone I`ve admired greatly for such a long time. The idea of writing songs with him is a dream come true."
Steven recently admitted he would love to see Johnny play him in a movie of his life and the 47-year-old actor would jump at the chance to portray the rocker.
He said: "I would give it a shot, why not."
Meanwhile, Johnny - who reprises his role as Captain Jack Sparrow in `Pirates of the Caribbean: On Stranger Tides` - has admitted he was pleased Rolling Stones guitarist Keith Richards agreed to return to the franchise as Captain Teague - because spending time with the legendary musician makes him feel like he is in a rock band.
He said: "To be able to bring him back into the `Pirates` fold, where he most certainly belongs, was a gas.
"Just spending a couple days sharing a trailer, it was as close, I suppose, as being in a rock `n` roll band with him as you can get."