Noun
A popular music production technique, developed in the 1960s, in which a number of musicians perform the same instruments or parts in unison and the resulting sound is re-recorded in an echo chamber.
A densely layered sound, often a piece of music.
Source: en.wiktionary.orgI started writing instrumentals but Roma pointed out they were very visual, so she started writing lyrics .. and Nicky had this idea of creating a wall of sound and started multi-tracking my voice. Enya
Phil Spector 's Wall of Sound recording technique was, it has been claimed, heavily influenced by Wagner. Source: Internet
Because of this, Alembic would play an integral role in the research, development, and production of the Wall of Sound. Source: Internet