It’s been 50 years since Pink Floyd released its first album but drummer Nick Mason says he didn’t think the band would last a year.

Mason and bassist Roger Waters made an appearance at London’s Victoria and Albert Museum Thursday, where an exhibit honouring the 50th anniversary of the band’s The Piper at the Gates of Dawn album is about to open.

On display will be more than 350 artifacts, including letters, sketches, handwritten lyrics as well as footage of the band’s live performances.

The exhibit is titled “The Pink Floyd Exhibition: Their Mortal Remains” – and will open to the public in May.