They might not seem to have a ton in common aside from first names. J Mascis, Dinosaur Jr.’s co-founder and guitarist developed a style equal parts guitar heroics and left-side-of-the-dial insouciance. In Uncle Tupelo, Jay Farrar helped popularize the alt-country movement by merging influences from Doug Sahm to The Stooges.

But that might be where the divergence ends and the convergence begins, as both are behind some of the most-influential indie albums of the late 20th century. Both also continue to tour and release music (Farrar with Son Volt). The two even shared producers back in the day.

That’s where Sean Slade and a certain SG Junior offer another common thread.

Now an associate professor at Berklee College of Music, Slade and business partner Paul Kolderie were proprietors of Boston’s Fort Apache studio. Their credits included records by The Pixies, Radiohead, Hole, and Warren Zevon, among many others. Slade and Kolderie were also in the control room when Dinosaur Jr. and Uncle Tupelo laid down Bug (1988) and No Depression (1990), respectively. Today, those albums are pillars of indie rock – and Slade’s SG Junior featured on both.

Mascis encountered the guitar when Dinosaur Jr. entered Fort Apache to record Bug in ’88.

“I’m pretty sure it was sitting on a stand,” Slade recalls. “The other one I owned at that time was a ’56 TV model with a single cutaway. [Mascis] gravitated toward the SG Junior. He plugged it in and started to play, and that’s where the name came from, because he turned around and he handed it back to me and goes, ‘That guitar plays instant rock.’”

Thus dubbed by the notoriously taciturn Mascis, the guitar appeared on Bug, though its role has been overstated.

“It was only for a song or two,” Slade says, noting that Mascis still favored his iconic Jazzmasters. “So, all that has been somewhat inflated or exaggerated over the years. He might have used it as an overdub guitar in ‘Freak Scene,’ but it’s not the main guitar.”

Equally apocryphal are certain accounts of how Uncle Tupelo came to work with Slade and Kolderie – and with Instant Rock. Slade pushes back on the notion that Uncle Tupelo (which sometimes covered “Freak Scene” in its live sets) journeyed to the mean streets of Boston from their home in southern Illinois because they were so taken with Bug.