For a young musician to crash, suddenly, into renown and adoration can be disorienting. Writing and performing songs may turn fraught with expectations. The road becomes home; communing with audiences of strangers stands in for human connection. It’s a dream — and also just plain weird.

At least Julien Baker, Phoebe Bridgers and Lucy Dacus have one another.

Each in their early 20s, all three have emerged in the last few years as singular forces in indie rock, earning acclaim for preternaturally sharp lyrics and commanding voices on albums that have set the bar for a new generation of singer-songwriters. They have also found common ground in their mutual isolation.

“It feels amazing to have people understand that I’m simultaneously so anxious and so bored and so busy all at once,” Ms. Bridgers said recently. “And so lucky.” Ms. Baker explained: “Things were happening for us all at the same time and I think we’ve gravitated to each other. Our personalities are really similar, how we view the world and our artistry and our position as musicians.”

A monthlong tour together this November was an obvious move. But starting a band on top of that was just more fun. What began as a plan to record a collaborative promotional single to advertise the concerts bloomed into a six-song EP by the trio, who have dubbed themselves boygenius — an inside joke that evolved into an ethos.