Investigation

If you have a favourite LP cover from the 1970s, there's a fair chance it will have been designed by Hipgnosis. Founded by Storm Thorgerson and Aubrey Powell, the pair had been inspired by other groundbreaking sleeve art. 'When we saw Sgt Pepper's, we went, "Oh, my gosh, there's another way of doing this… We can do this, but let's think differently"', Powell explained.

They certainly did, helped by the relationships they built with artists such as Pink Floyd. It was Hipgnosis behind the Droste Effect image on Ummagumma and the startlingly unusual 'cow' sleeve of Atom Heart Mother. Then a few months before they sat around a table with Paul and Linda to conceive Band On The Run, they created a cover design that rivals Sgt Pepper's in the iconic stakes. The simple, stunning prism image of Dark Side Of The Moon often dukes it out with Peter Blake and Jann Haworth's collage at the top of 'greatest ever LP sleeve' lists.

Other notable sleeves the pair masterminded include Peter Gabriel's solo albums (all self-titled but, thanks to the sleeve art, nicknamed self-explanatory things such as 'Scratch' and 'Melt'), 10cc's How Dare You?, Led Zeppelin's Presence and Genesis's The Lamb Lies Down On Broadway, Yes's Going For The One and AC/DC's Dirty Deeds Done Dirt Cheap. Their secret? Artistic freedom. 'We had the great privilege of being trusted by the bands we worked for', Powell told Rolling Stone magazine. 'It was amazing.'