"And I was plugged in. I had a natural sense of where the two records were spinning. At one point, 'Assembly Line' fell off the beat for a split second and I dog-paddled the record backwards. Spin back! Then I punched it forward right on the break ... Punch phase! Zuka-Zuka! It sounds like a beat! But the drummer didn't play it, I did! And the rhythm was still on time!" Grandmaster Flash, from The Adventures of Grandmaster Flash: My Life, My Beats. The revolutionary DJ spins tales from his book at 7:30 p.m. Tues., June 17, at Borders Books & Music in Buckhead (3637 Peachtree Road).