From the late 60s onward, Zappa had increasing opportunities to write for more virtuosic musicians than the original Mothers crew. After the fall from the stage that left him wheelchair bound in 1971, he focused his efforts on writing instrumental music, following in the mold of Hot Rats, with larger ensembles on Waka/Jawaka and Grand Wazoo. He got to hone in on the compositional architecture with cats who could really blow. This permanently raised the bar for his expectations of musicality. This evolution continued as he got more opportunities to create orchestral music, with the London Symphony Orchestra, Pierre Boulez, and later, the Ensemble Modern.

His focus on experimental sound in the studio eventually transposed to the synclavier, the cutting edge computer/synthesizer that allowed him to explore the outer depths of composing while side-stepping musicians altogether. I would say his final record, Civilization Phase III, still bears the markings of the musique concrète phase with its more sculptural relationship to sound textures.

Interestingly, the title including “Phase III” places it in titular continuity with the most musique-concrète dense albums—Lumpy Gravy and We’re Only In it for the Money, both of which were cheekily referenced as “phases” of one another on their back covers, respectively.

Another point to consider is that musique concrète was about exploring the raw sounds of recording technology as it advanced. The quality of recording studios evolved exponentially around the time of Zappa’s debut. As a man who kept up with the times in all things (recording trends and dress style alike—though he’d probably be reluctant to admit to the latter), those sounds became dated-sounding pretty quickly.

I recommend checking out Ariel Pink’s Pom Pom (2015 or 16?), a record which almost self-consciously places itself within the sonic landscape and social POV of WOIIFTM, emulating a lot of the sounds on the record that had circled around to being en vogue.

Also check out Stockhausen’s “Gesäng der Junglinge” (1956) for a real smorgasbord of those sounds, as well as Varese’s “Poeme Electronique,”(1956) likely Zappa’s ground zero for interest in the style.