In the field of experimentation, Electric Prunes played a decisive role in the second half of the 1960s. Their albums, brimming with energetic sonic intensity, were probably one of the precursors to underground and progressive rock, opening new musical avenues for the groups that later made the definitive leap into avant-garde sounds. Formed in Los Angeles in 1965, they left behind an interesting and ambitious collection of great albums worthy of study, such as "The Electric Prunes" (1967), their first album, which served as the basis for their next album, "Underground", their second LP, whose title already hinted at the group's musical direction. On "Underground" (1967), the group's growing psychedelic and experimental vision was evident, though it would ultimately go unnoticed by the general public. In this album, "Underground" (1967), the group's growing psychedelic and experimental vision was evident, though it would go largely unnoticed by the general public. "Mass In F Minor", their third album, was even more experimental, a concept album closer to a rock mass than a conventional rock record, and to make matters even more complex, it was sung in Latin. This unreleased, misunderstood, and unusual work nearly led to the band's breakup. However, in 1968, they released their next album, "Release Of An Oath", which, continuing in the same vein as its predecessor, didn't achieve much commercial success, but curiously, it was immortalized in the famous film "Easy Rider" thanks to the track "Kyrie Eleison", "Just Old Good Rock and Roll" was the epitaph for Electric Prunes, who, despite returning to their original sound, were another complete commercial failure. Years later the band would reunite for some concerts and several compilations and live recordings from their heyday were released, such as the magnificent "Stockholm 67" recorded in 1967 during a European tour, released more than 30 years later, in a historic recording considered one of the best live shows of the psychedelic era.

