There's no doubt that technology is changing the way we handle our history. Now conversations — once ephemeral — can be preserved forever — if no one holds down the erase button. Nowhere is this change more evident than in the world of Presidential politics. In recent years, recordings from the Kennedy, Johnson and Nixon administrations have become available to the public.

Historians have been quick to make a new sub-genre out of interpreting these tapes. Columbia University's Alan Brinkley, finds them an incomparable source: "No collection of manuscripts, no after-the-fact oral history, no contemporary account by a journalist will ever have the immediacy or the revelatory power of these conversations." But the tapes themselves make fascinating listening for anyone and many are available to you now online.

This week Bill Moyers reflects on a conversation between Lyndon Johnson and his National Security Advisor McGeorge Bundy that took place in 1964. Check back for streaming audio and video — in the meantime explore the audio world of the White House through the links below and talk back on the blog.