The term 'YARDBIRDS DO IT' is a reference to the British rock band The Yardbirds, who were active from 1963 to 1968. The four-letter solution for this term is TIME, which is an appropriate answer given the band's history. The Yardbirds were known for their innovative approach to music, which included experimenting with different genres and incorporating elements of blues, folk, and jazz into their sound. They also had a knack for creating catchy hooks and memorable melodies, which helped them become one of the most influential bands of the 1960s. As such, it makes sense that the solution for this crossword clue is TIME, as the band's legacy will live on forever.