This episode’s guest is one of those rare studio minds who makes the control room feel less like a workplace and more like a laboratory with excellent taste.

Sylvia Massy is a producer, mixer, and engineer whose credits stretch from punk grit to arena-scale rock and beyond. Her name is often spoken as she produced Tool’s Undertow, but her story doesn’t start with platinum plaques. It starts in the mid-’80s trenches, making compilations, working with punk bands, engineering metal records, and learning the kind of hard-won lessons you only get when the tape is rolling and the stakes are real. From there, she becomes a crucial behind-the-boards force in Los Angeles, intersects with the Sound City recording studio mythology, and winds up in the orbit of Rick Rubin’s American Recordings era, touching projects that helped define what “big” sounded like in the ’90s.

But the reason I wanted Sylvia on the show isn’t just the résumé. It’s the method. Sylvia is obsessed, in the best way, with recording technology and the physical stuff of sound. Consoles, mics, outboard gear, oddball techniques, and the kind of creative decisions that make an outsider sit up and pay attention. Her approach is curious, practical, fearless, and frequently hilarious.

We also talk about Studio Confidential, a new live, in-person onstage conversation series launching in New York City. It’s designed to pull back the curtain on legendary sessions and the people who actually built those records from the inside out. The official residency runs February 3 through March 1, 2026 at NYC’s Sheen Center for Thought & Culture, with multiple shows each week.

If Studio Confidential is about pulling back the curtain, Sylvia’s the person you want holding the flashlight.