Conversation so far:
What is progressiveness?
Elements contributing to the progressive label include: lyrics were more poetic, technology was harnessed for new sounds, music approached the condition of art, and the studio became the focus of musical activity
What is psychedelia?
Psychedelic music (sometimes called psychedelia is a wide range of popular music styles and genres influenced by 1960s psychedelia, a subculture of people who used psychedelic drugs

Question: How did the Beatles contribute to progressiveness?
Self-contained rewrite: How did the Beatles contribute to progressiveness?