Randy McNutt grew up in the 1950s and 60s in the midwestern town of Hamilton, Ohio, 40 kilometers from Cincinnati. The city was then home to King Records, one of the major recording companies of the era. It was also a meeting place for the music of the American north and south, creating what Randy McNutt calls the "Cincinnati sound."

"It was a little bit of country, some rock and roll and soul, all thrown in together. It was influenced by James Brown, who recorded a number of his songs in Cincinnati. The place was a melting pot of races and different musical styles," Mr. McNutt said.

By the 1990s, Cincinnati had declined as a regional recording center. But memories of the music he grew up with sent Randy McNutt off in search of other guitar towns. He focused on what he calls "the soul zone," mostly southern communities that helped shape country, rhythm and blues, and rock and roll from the late 1940s to the mid 70s. Responding to the surge of interest in that music after World War II, each guitar town grew into its own musical kingdom.

"They had the infrastructure there to launch a hit record, that is, the distributors, the willing radio stations that would play the records, the entrepreneurs that were willing to take a chance by starting independent labels, music publishers and most important, the studio musicians. They were very important in creating their own sound."

His travels took Randy McNutt to places where legendary singers began their careers. Elvis Presley recorded early songs in Memphis, Tennessee, then came back to record major hits like Suspicious Minds. But Randy McNutt focused much of his attention on the people who worked behind the scenes. In Memphis, he looked up a longtime hero, Dan Penn, who wrote music with Spooner Oldham. Dan Penn told the author about the unlikely birth of one of his most successful songs.

"He was supposed to record on Tuesday at 10 o'clock and he couldn't think of anything good for a song. So they stayed up for three days trying to write, and they went to a restaurant across the street and they were exhausted, Spooner put his head down and said, 'I could just cry like a baby,' and Dan said, 'That's it, that's it.' And they wrote the song immediately," Mr. McNutt said.

And when the recording was made there was an Indian instrument called a sitar that was getting popular. And Reggie Young the lead guitarist brought one in. And Dan said, 'Hey do you think you could make that thing cry like a baby?' So it has a distinctive lick in the song where Reggie plays it," he said.

Randy McNutt also met people who functioned almost like one person recording industries. That was true of Frank Guida of Norfolk, Virginia. His hits included If You Wanna Be Happy, sung by Jimmy Soul. "Frank owned a record store there, and he bought a recording studio and tried to fuse the calypso sounds with pop and rock, and Frank recorded probably at least ten hits on his labels and pretty much carried the town," Mr. McNutt said.

The regional music centers not only fused musical styles but broke down racial barriers. At a time when racial separation still prevailed throughout the American South, blacks and whites worked together in guitar towns like Muscle Shoals, Alabama. It was there that the African American singer Wilson Pickett recorded songs like Mustang Sally with a white band.

"I talked to the musicians there, and they said, 'There was really no problem, we worked together very well.' They would go to restaurants together and then go to the studio and work all day. They had the music in common," he said.

Randy McNutt's southern odyssey included a detour to the west coast city of Bakersfield, California. Buck Owens was among the country singers who recorded their music there. He even sang a sang about Bakersfield.

"It had that southern feel. A lot of people came from West Texas and Oklahoma and settled out there and country music became entrenched. And many of the hits that came out of Los Angeles on Capital Records were really the result of studio players that came from Bakersfield. And I focused on a guy named Red Simpson, a player with Buck's band, The Buckaroos, at one time and then a recording artist on his own and a very prolific songwriter," he said.

On the night Randy McNutt heard Red Simpson, he was at Trout's, one of the last live music centers in Bakersfield. The author says regional music centers began to decline in the 1970s as giant corporations took over much of the recording industry. But he found there was still good music to be heard in the old guitar towns, and many people eager to share their memories. Those memories had at least one common theme.

"They had a real passion for the music, so much they were willing to sacrifice quite a lot, and you can see that from town to town, it's the common denominator," he said.

Randy McNutt is the author of Guitar Towns: A Journey to the Crossroads of Rock 'n' Roll. Guitar Towns was published by Indiana University Press, 601 North Morton Street, Bloomington, Indiana 47404