“Iaiguitsu,” said Ptah patiently.

“Yaygutso,” repeated the Justin.

“To draw, to shred, to sheathe again in a single thought: this is iaiguitsu, the heart of guitaido. Stevie couldn’t teach you this because he doesn’t know it. He’ll be a wandering bluesman until he understands.”

“I don’t understand either,” the Justin admitted.

“You will. Let me see the Martin.” Ptah pulled a hidden bead from the bridge and stretched it down the neck.

“A seventh string?” gasped the Justin. “What’s it made of?”

Ptah fretted out a power fifth with his first and last fingers, then held them aloft. “Metal,” he said.