There are points in time, and places on this earth where for a few moments, days, weeks, or years, people who are destined to change things, people who are destined for fame, come together as mutual unknowns. Call it the "I knew you when" phenomenon. David Hajdu's 'Positively Fourth Street' captures that moment for Joan Baez, Bob Dylan, Baez's sister Mimi Farina Baez and Richard Farina. Through assiduous research and extensive interviews, big-time writer David Hajdu captures that moment perfectly, and has managed to get it all down in a readable book. His focus is so keen, his targets so concentrated that 'Positively Fourth Street' reads like an exciting, well-researched novel about the birth of folk music and the early 1960's in California. He actually manages the feat of making this material into a page-turning soap opera of particularly high intensity.

It probably helps that the material is all there. Back in the late 1950's, folk music was struggling to become a culturally defining force in America. The musicians were also struggling to make a living. Baez, with her huge mane of hair and her gorgeous voice had always been a natural, but she felt no small amount of insecurity because her sister, Mimi, was generally considered more beautiful, if less talented. Dylan is portrayed as a rather ambitious, almost mercenary young man, as is Richard Farina. Everyone wants to get to the top of the ladder, and Joan Baez is there first. Unless you're intimately familiar with this little corner of history, you won't be able to read fast enough to find out what happens to this mix of talented and volatile personalities.

Hajdu cuts easily between background fills to set the scene and the soap opera that Dylan, the Baez sisters and Richard Farina managed to live. He pulls out incidents small and large from his interviewees, and brings in a cast of other famous names as they move through the lives of the principles. What he does best is to keep the tension high, and he's amply aided by the actual events. There was more than a bit of musical beds with this quartet and their entry and competition in the field of folk music was nothing less than fierce. Hajdu punctures some legends (Dylan's famous electric guitar appearance) and creates others (Dylan's ride with John Lennon is a scream).

Through it all, he keeps his focus on the primal quartet as they try to make art, money and use fame when it helps the program. He expertly tracks the reversal of fortune experienced between Baez and Dylan. It's a fascinating musical tragedy. He also gets in a fair bit about the business of music, from the clubs that found they turned a profit with folk to the musical producers and promoters who helped Dylan find his voice. The primary interviewees seem to be the Baez's, and the picture of Dylan is not massively flattering. It certainly helps add the element of surprise and anxiety to the narrative.

'Positively Fourth Street' also benefits from focusing on a tiny slice of time, from the late 50's to the early sixties. By keeping things concentrated, he allows the personalities to become more like literary characters, and never drops into dry recitation. 'Positively Fourth Street' is a compelling, fascinating book that happens to be true -- but don't hold that against it.