The Woodstock tapes, revealed

A new CD box set, “Woodstock 50: Back to the Garden,” captures virtually every minute of audio from the 1969 music festival, from the performers to P.A. announcements and audience interactions. In an exclusive visit to the Warner Music Vault in Los Angeles, “Sunday Morning” producer Sara Kugel talked with music producer Andy Zax and audio engineer Brian Kehew about canvassing the archive’s rare holdings to create a 36-hour magnum opus chronicling an unparalleled event in music history: “Woodstock 50: Back to the Garden.”