A unique documentary of the seminal American rock band the Grateful Dead is on its way, centered around a 3-hour conversation with late lead guitarist Jerry Garcia, which was shot in 1987 at the peak of the band’s success. [Deadline]

Celebrated music documentarian Malcolm Leo shot the interview on negative film, complete with studio-quality lighting and production sound. Veteran talent manager John Hartmann (brother of late SNL alum Phil Hartmann) will co-produce the doc with Leo for their Leo/Hartmann Productions shingle. Leo intends to combine the interview with “an unprecedented amount of never-before-seen performances, documentary footage, and rare home movies.”

The pedigree of the filmmakers is top-notch: Leo previously worked on films about Elvis Presley, Crosby Stills & Nash and The Beach Boys. Hartmann’s resume includes stints as personal manager for Peter, Paul & Mary, The Eagles, CS&N, Poco, America, and others. The duo are finalizing financing and distribution with an eye toward releasing the completed doc in spring of 2012.

A clip from the doc was shown to 42,000 fans during Jerry Garcia Day at AT&T Park in San Francisco during a Giants game. The celebration was captured on film by co-producer Justin Kreutzmann (son of Dead drummer and founding member Bill Kreutzmann) and will be seen in the final film. The filmmakers were also granted full access to film Jerry’s eldest daughter, Annabelle Garcia as she threw out the first pitch, along with members of Further (featuring a rotating line-up of the surviving members of the Dead along with other notable “jam-band” musicians who carry on the Dead legacy) singing the National Anthem. Also, on par with the epic-level silliness the Dead were capable of, is a scene with a Guinness World Record-setting rendition of “Take Me Out To The Ball Game” by thousands of baseball fans on kazoos.

For 30 years – from 1965 until Garcia’s death in 1995 – the Grateful Dead toured relentlessly (since their indifference toward studio albums were reflected by their low sales), performing over 400 songs during the course of their 2,300 shows together. 1987 was a watershed year in the band’s history, as “Touch of Grey” became an out-of-nowhere hit single, propelling their album “In The Dark” to the top of the charts for awhile.

As a lifelong Deadhead myself, I can’t wait to see this. Grateful Dead films have come and gone – there’s an extensive catalog of the band’s 1990′s show available on DVD and several documentaries of varying quality (the best of which is probably 2003′s Festival Express, chronicling the wonderful time in 1970 when the Dead joined Janis Joplin, The Band, Buddy Guy and others on a train-ride festival tour through Canada) – but painfully few were granted access to the band’s legendary vault. This project sounds promising… the Dead have their haters, I know, but this doc might be able to really project the basic goodwill the Grateful Dead tried to generate during their career, and maybe even coax a new generation to get on the bus.

Are you a Grateful Dead fan? Are you looking forward to this film?