 Delay effects can be created using tape loops, an approach developed in the 1940s and 1950s ; analog  effects units, which were introduced in the 1970s;
<meaning-changed>  Delay effects can be created using tape loops, an approach developed in the 1940s and 1950s ; analog  effects units, which were introduced in the 1970s;
 Delay effects can be created using tape loops, an approach developed in the 1940s and 1950s and was used by artists including Elvis Presley and Buddy Holly. effects units, which were introduced in the 1970s;