The Big Spliff" was the shelved Pink Floyd album that became 'The Endless River'.

That’s the one. After The Division Bell (1994), Pink Floyd started recording a follow-up around 1995–96, working title The Big Spliff. It never got finished, and the tapes sat in the vault for nearly two decades.

When David Gilmour decided to do something with all that leftover material, he and the band (with some new bits from Richard Wright’s last sessions) shaped it into The Endless River (2014). So the unreleased album isn’t some lost alternate version — it’s the rough foundation that got remodeled.

Unless you’re a hardcore completist, you don’t need to hunt for bootlegs. The official release is the best realization of those sessions.