What is your favorite "solo" album of all time?

Recorded, yeah, but not mixed nor released...
When he approached JZ after the famous gig, it was in 74...
In 76, his "audition" led basically JP put his bass parts on Cannon Ball and replacing Alphonso Johnson ones.
He also came in the late sessions with a rough Barbary Coast and JZ and WS decided to let a track out (Wayne's Cigano) in order to include Jaco's number.

 

"Crosseyed Heart" by Keith Richards- released 2015, it has a bit of everything on it- jazzy blues, rock, soul, reggae. Keith really is the soul of the Stones.

 

Hate to bump, but I found the answer. Roy Wood's Boulders is the epitome of the word solo, released in 1973 but actually recorded in 1969 when The Move were still a thing.