Metallica guitarist Kirk Hammett has revealed the band included a deliberate reference to the iconic theme of the 1960s 'Batman' TV series in their song 'Shadows Follow'.

Fans of the thrash metal legends pointed out that a specific lead guitar riff on the track - which features on Metallica's 11th studio album '72 Seasons', released in April 2023 - has a striking similarity to the music from the show, which starred Adam West as The Caped Crusader and Burt Ward as Robin.

Kirk has now revealed that the group - also comprised of frontman James Hetfield, drummer Lars Ulrich and bassist Robert Trujillo - referred to the guitar part, which can be heard at four minutes 20 seconds into the track, as "The Batman Riff" during recording sessions for the LP confirming the fan theory.

When asked about the reference in an interview with Total Guitar magazine, he said: "That’s really funny, because we called that riff ‘The Batman Riff’, and I know exactly what you are talking about.”

Since the album was released, Metallica fans had been posting online about "The Batman Riff", with thread appearing on community site Reddit dedicated to it.

On the subreddit, one fan asked: "Anyone else here [sic] the 60s Batman theme song in Shadows Follow?”

Prompting a reply that read: "Yes! I immediately heard it and it honestly took me out of the song for a second.

Elsewhere in the interview, the 61-year-old rock icon mused on the importance of guitar solos in songs, and revealed that he has accepted that the majority of music fans don't really care about the technical skill displayed in a solo.

Kirk - who is widely considered to be one of the greatest guitarists of all-time - stated: "I hate to say it ... but non-musicians, who are the majority of the listening world, they are not going to remember guitar solos.

"They are gonna remember a great melody, and they’re really gonna remember a great song – especially a song that’s gonna bring them to a different place from where they were five minutes previously.”