James Allan Berkenstadt (born June 26, 1956) is an American writer, record producer, and historical entertainment consultant. Berkenstadt was born in Winnetka, Illinois, a suburb of Chicago. He is the third of three children born to Lois Berkenstadt, his mother, and Edward Berkenstadt, his father.
Berkenstadt, previously an attorney of many years, has consulted on a number of audio, video, and online projects for George Harrison, as well as for The Beatles' company Apple Corps and many others in the music industry.
After graduating from Northwestern University with a Bachelor of Science in sociology, Berkenstadt went on to get his law degree from Southern Illinois University. He passed the Illinois State Bar Examination in 1982 and the Wisconsin State Bar in 1985. In the 1980s, Berkenstadt was a litigation attorney in Chicago at Pollina & Phelan and then, after moving to Madison, Wisconsin, he continued working at the Axley Brynelson law firm. From 1987 to 2007, Berkenstadt served as vice president & general counsel at the Wisconsin Cheeseman, a gift and food manufacturing company in Sun Prairie, Wisconsin.
In 1994, Berkenstadt and co-author Belmo penned the book Black Market Beatles: The Story Behind Their Lost Recordings, aimed at fans interested in the recordings that the Beatles left in the vaults. Black Market Beatles is a part of the permanent Library and Archive Collection at the Rock and Roll Hall of Fame and Museum in Cleveland.
In September 1998, Jim and Charles Cross co-authored the book Nevermind Nirvana about the creation of the Nevermind album by Nirvana. It served to create the understanding behind how the album was so well received by the 90s generation of fans. Nevermind Nirvana is also a part of the permanent Library and Archive Collection at the Rock and Roll Hall of Fame.
From 1998 to 2000, Berkenstadt produced two historical albums of Big Band music that had been performed and recorded live on the rooftop of Madison's historic Edgewater Hotel. The albums, Live at the Edgewater Jimmy Dorsey and Woody Herman, and Live at the Edgewater: Tex Beneke, Stan Kenton & Ralph Flanagan, were released on the Soundworks Label. Berkenstadt has also received an RIAA Platinum record award for his work with Garbage (band) on their album Version 2.0.
Since the late 1990s, Berkenstadt has worked on a number of projects for George Harrison, including the Martin Scorsese Emmy-nominated film, George Harrison: Living in the Material World. He also contributed to the Beatles' Help! DVD box set, as well as VH1's Behind the Music.
Most recently, Berkenstadt has published his latest book, The Beatle Who Vanished, "a true account of Jimmie Nicol, an anonymous drummer whose journey from humble beginnings to an improbable climb rescued The Beatles' first world tour from disaster by temporarily stepping in for Ringo Starr."
- Live at the Edgewater: Jimmy Dorsey & Woody Herman (Producer) (1998)
- Version 2.0 by Garbage (Research and Website development) (1998)
- Live at the Edgewater: Tex Beneke, Stan Kenton & Ralph Flanagan (Producer) (1998)
- The Dark Horse Years 1976–1992 box set (CD + DVD research) (2004)
- Live in Japan by George Harrison (Hybrid SACD research) (2004)
- Cloud Nine by George Harrison (Research) (2004)
- Living in the Material World by George Harrison (CD + DVD research) (2006)
- Eye to Eye by Bandallamas (Co-executive producer) (2010)
- Black Market Beatles: The Story Behind Their Lost Recordings
- Nevermind Nirvana
- The Beatle Who Vanished (Released January 2013) 
- Citizen Hong Kong (Research) (1999)
- George Harrison: The Dark Horse Years 1976–1992 (Research) (2004)
- The True History of the Traveling Wilburys (Research) (2007)
- The Beatles in Help! (Research) (2007)
- George Harrison: Living in the Material World (Historical Consultant) (2011)
- American Bandstand's Teen Idol (Clip researcher) (1994)
- VH1 Behind the Music: Badfinger (Researcher) (2000)
- VH1 Behind the Music: Garbage (Researcher) (2002)
- Beatles Expert Jim Berkenstadt is a Rock 'n' Roll Detective, Citypages
- Recordings Preserve Hotel's Legendary Concerts, HighBeam Research
- James A. Berkenstadt – Lawyer Profile, Martindale.
- Vig, Butch, Enotes.
- Black Market Beatles: The Story Behind Their Lost Recordings, Amazon.com.
- Review of Black Market Beatles, Google Books Reviews.
- Doug Moe: Solving Rock 'n' Roll's Big Mysteries, Wisconsin State Journal.
- Black Market Beatles Rock and Roll HOF Listing, Rock and Roll Hall of Fame Library and Archives.
- Nevermind Nirvana Listing. Good Reads.
- Nevermind Nirvana Rock and Roll HOF Listing., Rock and Roll Hall of Fame Library and Archives.
- Jim Berkenstadt's IMDB Page, Internet Movie Database.
- Jim Berkenstadt: Music Historian, Archivist, Consultant, Author, and The Rock and Roll Detective, Americana Gazette.
- Official Website for The Beatle who Vanished a book by Jim Berkenstadt.