Recently, a few scholars questioned the thesis of a prophetic persona responsible for Isaiah 40-55/66. It has been argued (by Prof. Ulrich Berges and others) that temple singers / musicians (as we hear of them in postexilic literature, especially Chronicles) are responsible for Isaiah 40ff. This essay investigates that proposition from the viewpoint of the Asaphite Psalms and their corpus in the Asaphite part of the Psalter (Book III), as well as the "Deutero-Asaphite" part of the Psalter (Book IV). In an exemplary disposition, three interfaces between "Asaph" (Pss 50; 73-83; 90-106) and "Isaiah" (Isa 40-66) are examined: (1st) The reception and transformation of the Exodus-tradition in Psalm 77 and Isaiah 40-55; (2nd and most extensively) the way of dealing with catastrophic situations in Psalms 77-79 (plus Ps 106); and Isaiah 63:7-64:11; (3rd) the "new song" in Isaiah 42:10-13 (plus other hymns) and in Psalm 96/98. In the final part, observations and indications of these intertextual investigations are evaluated and summarised. There seems to be interesting proximities and interdependencies between the two textual strata, so that the thesis of (Asaphite) temple singers as the group responsible for composing, transmitting and / or editing (also) the exilic-postexilic part of Isaiah 40ff. can be substantiated. It must be admitted, however, that this study is only a test case and does not examine the levitical (Asaphite and Qorachite) Psalms or Isaiah 40-66 overall.