 However, recorders with four or more tracks were restricted mainly to major American recording studios until the mid-to-late 1960s, mainly because of import restrictions and the high cost of the technology.In England, pioneering independent producer Joe Meek produced all of his innovative early 1960s recordings using monophonic and two-track recorders.Like Meek, EMI house producer George Martin was considered an innovator for his use of two-track as a means to making better mono records, carefully balancing vocals and instruments; Abbey Road Studios installed Telefunken four-track machines in 1959 and 1960 (replaced in 1965 by smaller, more durable Studer machines), but The Beatles would not have access to them until late 1963, and all recordings prior to their first world hit single "I Want to Hold Your Hand" (1964) were made on two-track machines.