Jason Buckle is best known as a member of The All Seeing I which featured Jarvis Cocker amongst others on songwriting and vocal duties. In 2001, his band, Fat Truckers remixed Sunrise for Pulp and toured with them playing percussion and as their support. He formed Relaxed Muscle with Jarvis in 2002. In 2005, he featured on the three songs that Jarvis wrote for the Harry Potter and the Goblet of Fire soundtrack.
Jason has been touring with Pulp since 2024, playing percussion. He also co-wrote the song Spike Island which was inspired by his experience at the Stone Roses' gig of the same name.