Hard to tell. I asked Grok and there’s conflicting answers to whether the solo was comped:
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David Gilmour has spoken about his process for the "Comfortably Numb" solos in various interviews. In a 2015 *Guitar World* discussion, he explained that the solos—both the first (middle) and second (outro)—were crafted from multiple takes. He described recording "five or six solos," then charting the best parts and creating a composite by fading between them in the mix. This suggests the final solo, including the pinch harmonic, was part of a constructed performance rather than a single live take. However, he doesn’t specifically address overdubbing that pinch harmonic separately. Given his meticulous approach and the seamless integration of the note, it’s likely he played it live during one of those takes rather than adding it later.
Bob Ezrin, co-producer of *The Wall*, has offered conflicting accounts that muddy the waters. In a 2022 *Total Guitar* interview, he claimed the "second solo" was a first take, calling it a magical moment that overwhelmed him emotionally. However, Roger Waters disputed this in a 2023 YouTube Q&A, asserting Ezrin wasn’t even present for the second solo’s recording—saying it was done with James Guthrie, involved "umpteen takes," and was edited together. Ezrin later clarified (via a Reddit post attributed to him) that he misspoke about the "second solo," meaning his "first take" comment applied to the middle solo, not the outro. This doesn’t directly address the pinch harmonic but implies the outro solo’s recording was a separate, multi-take process under Guthrie’s supervision. Ezrin’s absence from that session leaves open the possibility of overdubbing, though he doesn’t mention it.
James Guthrie, the engineer and co-producer, is key here, as he oversaw the outro solo’s recording. In a *Brain Damage* interview, Guthrie detailed his role in *The Wall*’s production but didn’t specifically address the pinch harmonic. He’s known for his editing prowess, and Waters’ account credits him with stitching together the best bits of Gilmour’s takes. Guthrie’s work on the solo aligns with Gilmour’s composite method, suggesting the pinch harmonic was likely captured within those takes rather than dubbed in post-production—unless an unmentioned overdub session occurred. No explicit evidence from Guthrie confirms it was added separately.
Production notes from *The Wall* sessions (like those in Mark Blake’s book *Comfortably Numb: The Inside Story of Pink Floyd*) indicate the album was recorded across multiple studios—Super Bear in France, Miraval, and later in New York and Los Angeles—due to tax exile and scheduling. The outro solo was finalized after initial tracking, with Gilmour and Guthrie working together while Waters and Ezrin were elsewhere. Overdubs were frequent, especially for orchestral parts by Michael Kamen, but guitar-specific overdubs are less documented. Gilmour’s use of a Big Muff and delay (noted in *Guitar World*) for the solo’s tone doesn’t inherently require dubbing the pinch harmonic—it’s a technique he could execute live, as seen in countless performances (e.g., *Pulse* 1994).
The disagreement between Waters and Ezrin complicates things. Waters’ claim of "umpteen takes" edited by Guthrie contradicts Ezrin’s "first take" narrative, but neither mentions the pinch harmonic being dubbed in. Gilmour’s own words lean toward a crafted solo from multiple passes, not a single overdubbed note. Given his technical skill and the lack of specific evidence for a separate pinch harmonic overdub, it’s most plausible it was played within one of the takes and refined in the mix.
In conclusion, based on Gilmour’s composite method, Guthrie’s editing role, and the absence of explicit overdub mentions, the pinch harmonic was likely not dubbed in separately but was part of the original takes blended into the final solo. The *Wall* sessions were chaotic and layered, so I can’t rule it out entirely without a smoking gun (like a studio log), but the evidence tilts against it being a post-production addition.
