Bandcamp Tempo Adjust: DJ Extension With BPM Control
Seattle DJ Bobby Azarbayejani created free browser extensions that add CDJ-style tempo controls and BPM detection to Discogs and Bandcamp music previews.
How Tempo Control in Your Browser Rewires the Art of Digging
Seattle DJ Bobby Azarbayejani (nohup) shipped two free browser extensions that transplant CDJ pitch controls directly into Discogs and Bandcamp preview streams. Bandcamp Tempo Adjust launched December 2022; Discogs Tempo Adjust followed in November 2024, both available for Chrome and Firefox with open-source repositories on GitHub.
The toolset mirrors hardware workflows: a tempo slider mimicking CDJ faders, BPM jump buttons (±6, ±10, ±16, and a ±99% "WIDE" range), plus Master Tempo mode for pitch-independent speed shifts. Bandcamp's version adds BPM detection across albums and CSV export for purchase lists—features that turn passive browsing into set prep. With 10,000+ Chrome users and a 4.9/5 rating, the adoption signals genuine utility.
Azarbayejani cites chopped-and-screwed aesthetics as the catalyst: "I'm a big fan of chopped-and-screwed music and love experimenting with slowed-down tracks," he told Resident Advisor. The November UI refresh—grid layout, tighter integration—earned social-media buzz from DJs testing real-time pitch experiments mid-dig. Whether Web Audio API constraints limit compatibility across all preview formats remains unclear, as does long-term stability if platform architectures shift.
A Free Extension Brings CDJ-Style Pitch to Every Preview
The Bandcamp extension now ships with BPM detection for albums and individual tracks, plus a CSV export feature for purchase history—a workflow upgrade for DJs archiving their dig sessions. Updated in November 2024, the interface gained a grid layout that streamlines navigation between the tempo slider, jump buttons, and Master Tempo toggle. With 10,000+ Chrome users and a 4.9-star rating across 35 reviews, the tool has carved a niche among DJs who preview sets entirely in the browser before opening a DAW or booth software.
Azarbayejani told Resident Advisor he "initially made Bandcamp Tempo Adjust for myself" to experiment with chopped-and-screwed aesthetics, a process that previously required bouncing files out of the browser. The Discogs counterpart extends the same pitch-manipulation layer to used-vinyl listings, where sellers rarely provide audio samples longer than thirty seconds. Both extensions operate client-side via the Web Audio API—no server uploads—and collect no user data beyond functional telemetry, according to the Chrome Web Store listing.
The developer opened a fundraising page to sustain development, signaling ambitions beyond a side project. Long-term viability hinges on Discogs and Bandcamp preserving their current player architecture; major platform redesigns could break the extensions overnight.
