The estate of the “Purple Rain” singer — who died of an accidental opioid overdose in 2016 — is set to unveil a collection of the estimated 8,000 unreleased songs he kept hidden in a vault at his Paisley Park studios near his hometown of Minneapolis. His posthumous 12-track anthology is scheduled for release in late July, and will debut on CBS’s “60 Minutes.”“Prince’s enigmatic and prescient statement album #Welcome2America will be released July 30, 2021, by The Prince Estate and [Sony Legacy