It’s been 40 years to the day since Marvin Gaye died in Los Angeles – shot dead by his father after Gaye stepped in to break up an altercation between his father and his mother – a day before his 45th birthday. Now, a collection of unreleased Marvin Gaye recordings has been unearthed in Belgium after more than 40 years. The tapes apparently have 66 demos of new and and previously unheard songs that the soul singer behind hits like ‘What’s Going On’, ‘Let’s Get It On’ and the duet ‘Ain’t No Mountain’ with Tammi Terrell, recorded while in the country in the early ’80s. He left the tapes with Cha…