The influential album was released to very little acclaim in 1975 but has since gained status as a cult classic, but Smith was not planning to celebrate the milestone until she realised it was a chance to pay tribute to close friends and loved ones who have died since the record was released.

After a random meeting with a fan on the streets of New York City, Smith decided it would be a fitting gesture to organise a 40th anniversary Horses tour of the U.S. and Europe, which starts in October (15).

She tells Mojo magazine, "It was really by accident. I was walking in New York, and a kid of about 20 said hello, and told me next year will be Horses 40th anniversary, were we planning something special? I hadn't even contemplated it until then. But (guitarist) Lenny (Kaye) and I are pressing 70. We've reached many milestones together, alongside the band, so it seemed a perfect time to celebrate our lives together and the many friends and colleagues who are no longer here."