Final answer:
Phil Spector's distinctive production style is known as the 'Wall of Sound', characterized by its dense, reverberant, and orchestral effect created using innovative studio techniques.
Step-by-step explanation:
Phil Spector's productions were renowned for their distinctive sound which was so unique that it has its own moniker: the Wall of Sound. This term describes a lush, layered sound resulting from Spector's innovative studio techniques, which involved using multiple instruments to create a dense, reverberant and orchestral effect. The Wall of Sound was a significant departure from the clearer, simpler production styles of the time and became a hallmark of many hit records in the 1960s.
Spector achieved this sound by recording groups of musicians playing the same parts in unison, overlaying multiple instrumental tracks, and making extensive use of echo chambers. Iconic songs like 'Be My Baby' by The Ronettes and 'You've Lost That Lovin' Feelin'' by The Righteous Brothers are classic examples of the Wall of Sound technique. Through this production style, Spector hugely influenced the development of popular music production.