Tony Iommi recently spent an afternoon with his friend and fellow guitar hero Brian May of Queen making a documentary on riffs, and also traded guitars for fun.

• READ MORE: David Ellefson says fans are tired of his fight with Dave Mustaine: “We’re their fucking heroes, man. We changed their lives”

Iommi, who is one of the most famous left-handed guitarists in history, had to face the challenge of playing Brian May’s iconic electric guitar, the Red Special, upside down. The Red Special is a custom-made guitar that May and his father built in the early 1960s, using various materials such as wood from a fireplace and motorcycle valve springs. The guitar has a distinctive reddish-brown colour and a unique sound that has been featured on many Queen classics.

May, on the other hand, tried to play Iommi’s JayDee Custom SG-style guitar, which has a black finish and crucifix inlays on the fretboard. This guitar is one of Iommi’s signature models, and he has used it on many Black Sabbath albums and tours since the late 1970s. May also had a go at Iommi’s St Moritz replica of his famous left-handed 1965 Cherry ‘Monkey’ Gibson SG Special, which he used on some of Black Sabbath’s most influential records in the early 1970s.

View this post on Instagram

A post shared by Brian Harold May (@brianmayforreal)

May shared a short video clip and some photos of their guitar swap on his Instagram account, with the caption: “Joy! A rare and special afternoon with my dear pal Tony Iommi making a documentary on…. riffs! Rock on, folks!”

The video clip shows Iommi holding the Red Special upside down and strumming it awkwardly, while May smiles and laughs. The clip has no audio, so it is not clear what riffs they were playing or how they sounded. There is also no further information on the documentary on riffs that they were making.