British songwriters, musicians, producers, arrangers, actors, and filmmakers. Lennon and McCartney were the chief writers for the Beatles, the rock quartet by whose success all other groups are now measured. Without formal musical training, they created music that had universal appeal, yet was sophisticated enough to be appreciated by musical scholars. They expanded the boundaries of popular music, gave it respectability, and helped to bring it, both artistically and commercially, to its present state. The Beatles played a major role in defining the cultural climate of the sixties. From their hair and clothing to their interests in drugs and meditation, young people emulated them and their lifestyles. The Beatles achieved an uncanny balance of personality and talent, with each member of the group (which also included George Harrison and Ringo Starr) strongly individual as well as complementary to the others. Their music reflected this diversity: Lennon wrote songs that were often rebellious, aggressive, and satirical; McCartney's were lyrical, sweeter, and more sentimental. As songwriters, the difference in their natures seemed to aid in the success of their collaborations as each complemented the other's writing style. Later Harrison also became a composer, and his works most often reflected his interest in Eastern music and mystical thought. The Beatles, along with Bob Dylan, are considered responsible for renewing an interest in the power of words to the listening audience of the sixties. From the beginning, their lyrics were fresh and devoid of cliché. As they matured, their songs increased in complexity, and they moved from boy/girl romantic themes to subjects infrequently used in popular songs. Lennon's "Norwegian Wood," for instance, dealt with a clandestine affair, and McCartney's "Eleanor Rigby" painted a touching picture of the life and death of a lonely