 The material on the first two albums was largely constructed out of extended jams of blues standards and folk songs . This method led to the mixing of musical and lyrical elements of different songs and versions , as well as improvised passages , to create new material , but would lead to later accusations of plagiarism and legal disputes over copyright . Usually the music was developed first , sometimes with improvised lyrics that might then be rewritten for the final version of the song . From the visit to Bron @-@ Yr @-@ Aur in 1970 , the songwriting partnership between Page and Plant became predominant , with Page supplying the music , largely via his acoustic guitar , and Plant emerging as the band 's chief lyricist . Jones and Bonham then added to the material , in rehearsal or in the studio , as a song was developed . In the later stages of the band 's career , Page took a back seat in composition and Jones became increasingly important in producing music , often composed on the keyboard . Plant would then add lyrics before Page and Bonham developed their parts . 
