In late 2012, the couple was lounging in bed, watching television, when they received a random phone call “from someone who said that he was with 10 other people and he would like to come over for karaoke,” Mr. Williams recalled. “I said, ‘I’m sorry, but you’re calling my house.’”

The caller had stumbled across an old website for Lion’s Roar Entertainment, a mobile, for-hire karaoke and D.J. business that the couple closed in 2008 — save for a rare gig here and there — to focus on their other careers. Mr. Williams was a vocal music teacher, and Mrs. Soler-Williams, a television postproduction supervisor.

But by the following weekend, more people were calling, eager to sing karaoke at their house.

“I don’t know what that one guy did, but he bumped Lion’s Roar Karaoke to the very top of the search engine somehow,” Mr. Williams said. “It was like the Google algorithm was suddenly in our favor,” Mrs. Soler-Williams said.

Within a few months, visitors started showing up at their front door (the old website also listed their mailing address).

After over three years of fielding calls and turning away visitors, the couple began to wonder if they were missing an opportunity.