Time varying delay lines are fundamental building blocks for delay effects, synthesis algorithms, and computational acoustic models of musical instruments.
In the category of delay effects, variable delay lines are used for
(While reverberators need not be time varying, nowadays they typically are [#!Dattorro97!#,#!Blesser02!#].)In digital waveguide synthesis, variable delay lines are used for
The following sections will elaborate on the use of variable delay lines for effects. Their use in digital waveguide models will be deferred to a later section.