Here is some updated information about Jimi's "Black Gold" project.
Many thanks to fellow fan Mac again for this - source is JImpress magazine.

Eric Burdon's recollections: "I remember Jimi telling me about his idea for Black Gold... an autobiographical, multi-song fantasy piece he had been working on. Jimi intended it to accompany an animated feature about a black rock star - himself on the road... forty minutes of fresh new material that clearly demonstrated the direction Jimi was headed in. He talked excitedly about the cartoon character he'd envisoned for it. I know he did at least some work on the suite before he died."
(Straight Ahead fanzine)

Rumours circulated for years after Hendrix' death about a project called "The Black Gold Suite" which Jimi had mentioned in interviews. "Black Gold" was described as a "cartoon character" but whether Jimi intended completing the project in this form is unknown. In late 1970, he seemed to be working on simply a new album of songs without any particular concept attached to it. His left-over studio tapes eventually came out on the posthumous albums Cry Of Love, Rainbow Bridge and War Heroes (padded out with earlier recordings and a live track).

Then, in a March 1975 interview Alan Douglas referred to a tape of Black Gold that he had put together with Jimi in a hotel room. He said that they used a tape recorder which permitted them to overdub a second guitar part. Jimi had expressed his desire to make a Black Gold album and animated movie. In the 80s, Douglas mentioned that the tape featuring that Black Gold demo with an overdub had been stolen with other possessions from Jimi's New York apartment after his death. The stolen tape has never surfaced.

Luckily, another Black Gold tape exists! Back in July 1970, while filming for the movie "Rainbow Bridge" in Maui, Hawaii, Jimi had given drummer Mitch Mitchell six cassettes wrapped inside a bandanna for safe keeping. An acoustic solo demo of the Black Gold Suite was among them. Apparently unaware of the significance of the tapes, Mitch looked after the cassettes for two decades before entering into negotiations with Alan Douglas with a view to releasing the material. This particular tape features Jimi on acoustic guitar, without no extra guitar overdub.

The tracks were recorded on a two track Entronic C90, stereo cassette at Jimi's New York apartment sometime between February and April 1970. Kept in a black Ampex tape box with "BG*" written in Jimi's hand, the cassette label is annotated in Jimi's hand "Idea for L.P. Side 1 suite.. Black Gold" and, apparently, the cassette appears well used. The tracks it contains are as follows:

Suddenly November Morning
Captain Midnite (Captain 1201)
Loco Commotion
Here Comes Black Gold
Stepping Stone
Little Red Velvet Room

The Jungle Is Waiting
Send My Love To Joan Of Arc
God Bless The Day
Black Gold
Machine Gun
Here Comes Black Gold
Trash Man
Astro Man (Part 1)
Astro Man (Part 2)
I've Got A Place To Go

In 1992, Hendrix researcher and biographer Tony Brown (deceased) got to hear the tape while he was on a mission to interview Mitch Mitchell. What follows is based on his recollections of what he heard.

It's known that Jimi worked on tracks such as the opener "Suddenly November Morning" in March 1970 at the Londonderry Hotel in London, as hand-written lyrics exist, giving us a guide to when the recording was made. Jimi apparently played the tracks as a continuous medley with one running into the next. He had referred to "Black Gold" in interviews, "I wanted to get into sort o', what you would probably call, just pieces, yeah pieces behind each other like movements or whatever you call it. I've been writing some of those, but like I was into writing cartoons mostly, you know, Cartoons, music cartoons." This explains the birth of such characters as Astro Man and Captain Midnite. Tracks with familiar titles, such as "Drifting", "Stepping Stone" and "Astro Man", stick close to the released versions of the songs while "Send My Love To Joan Of Arc" has the same chord sequence as the familiar "Send My Love To Linda". Allegedly, "Little Red Velvet Room" refers to a child, Tami, whose mother, Diane Carpenter, claimed was Jimi's from a relationship in mid-1966, unfortunately this song comes to a premature end as the tape runs out.

Side two opens with the jazzy flamenco piece "The Jungle Is Waiting" with Jimi providing the jungle sound effects throughout. Another known song is "Machine Gun" which has Jimi concluding with the line "Thank Hell for Heaven, thank Heaven for Hell." The reprise of "Black Gold" features the lyric "He comes from the land of the Gypsy Sun" which seems to combine Jimi's common themes from "Hey Gypsy Boy" and "Hey Baby (New Rising Sun)", though it is unclear whether the music bears any resemblance to these two songs. Next comes "Trash Man" a very short song with lyrics, it bears no resemblance to the instrumental "Trashman" on "Hear My Music". "Astro Man" is in two parts with Jimi depicting himself as the hero, saving a girl on an LSD trip from falling to her death in the second part. In the final track Jimi holds an imaginary telephone conversation with someone called Rosie who invites him over and "I've Got A Place To Go" closes the tape.

In March 2010, Janie Hendrix had announced ed that Black Gold would be released "this decade". Here we are more than ten years later and it has yet to appear. However, the opening song of the tape - "Suddenly November Morning"  - was thankfully featured in the West Coast Seattle Boy box set (2010). Come on Janie, give us the entire recording!