Falling somewhere between traditional pop and R&B, the sound of the Girl Groups was one of the most popular rock & roll genres in the early '60s. Though there were strong elements of rock & roll and R&B in the music, the girl group sound was decidedly more polished than earlier forms of rock & roll. It was driven by producers and songwriters, who helped guided the groups and gave them material to sing. The vocalists had roots in gospel and R&B, while the songwriters and producers were schooled in traditional pop, which resulted in an exciting hybrid. The songs were innocent and yearning, with sweet, catchy melodies and driving backbeats. Though the girl groups faded away in the mid-'60s, they had a profound influence on pop/rock, particularly British Invasion acts like the Beatles.