The Beatles needed to record seventy new songs within nine years, between 1967 and 1976, to complete their contract. They believed that once they delivered those seventy recordings, they would be free to go to another record company. Between all the songs they wrote in India, and their backlog of older songs, they knew they could finish the job. They recorded demos of many of the songs at George Harrison's house, using his four-track tape recorder, then began work on the album at Abbey Road Studios in London.