1) Create a classical "tap delay" structure in PD.  All of the objects required for this patch can be found in the attached document, "delay_requirements.pd".  You may also wish to refer to the PD "Help" browser found in the help menu, especially "3.audio.exmaples/GO2.delay.loop.pd".  Please download the PD-extended application for your operating system from this site:

PD-extended installers

2) Read "Though the Sensory Looking Glass: The Aesthetic and Serial Foundations of Gesang der Jünglinge" in hard-copy in B27 in B27 discussing Stockhausen's "Gesang...".   It can also be found through JSTOR here:

JSTOR Reading

You may also wish to review the attached PDF by John Smalley, a more condensed and rather introductory essay.