Common sense probably gives one an idea what a loop is. In audio it is a sound that continually repeats itself over and over again. It is called a loop because back in the “old days” tapes were used. One could cut a section of tape out with a sound or passage and connect the end of it back to the beginning and form a physical loop. The audio would repeatedly play over and over in a tape machine. This innovation was used by companies who manufactured tape based looping delay or echo units such as the Echoplex and Roland Space Echo. The 8-track tapes of the 1970’s were an endless loop system. They never had to be rewound. In digital keyboards “looping” became a standard way to allow the sustained part of a sound to decay without having to have an actual (memory hungry) recording of the entire decay of the sound. Most sustained musical sounds fall into a relatively static state after a second or two. At that point it is possible to loop the static portion of the sound and have it play over and over while a VCA (or pick the name of this function in your synth) cause it to fade away simulating the actual decay of the instrument. “Looping” is the process of finding good loop points in sounds so they can be made to take on desired characteristics while looped. Often it is desired to loop sample so it accurately recreates some instrument, which can be quite difficult. In the 1980’s and 90’s looping became an art form and quite often loops would make or break sounds used in digital instruments. In recent years audio loops of entire musical passages have become very popular. A looped rhythm section, for example, can be a great foundation for another tune or arrangement.