What does a sold-out crowd at The Catalyst on a rainy Friday look like? Sweaty. Dripping off the backs of young hipsters, sliding down the walls, permeating the whole dance floor in a hazy shroud of fumes.

I sat down at a table above the stage, watching a throng of people file into the room. Two girls screamed loudly, “Oh my God, Dr. Dog!” while people lit joints and began dancing. The lights dimmed, the band took to the stage, the audience roared. I sat silently, with my notebook in my hands, pretending I was Lester Bangs from “Almost Famous” and channeling his cool, detached demeanor.

Through the haze, Philly-based band Dr. Dog played upward of 20 songs spanning their 15-year-long career. With recent record “B-Room” released in October 2013 to critical acclaim, the band has since been on a string of tour dates, building momentum with each stop across America.

These six musicians make it their point to be on the road, as over the last three years, their live shows have steadily become known as some of the most high energy performances in the modern indie rock scene. The band’s style explores the intersections between Americana, psych-pop and indie rock, as their songs often fluctuate between smooth, soulful ballads and frenetic, guitar-heavy jams.

After hearing their early lo-fi material around 2004, popular indie band My Morning Jacket became enamored with them. When lead singer Jim James heard Dr. Dog’s first album “Toothbrush,” it “reminded him of falling in love with music for the first time,” lead guitarist Scott McMicken said in a Philadelphia Weekly article. James then invited them to open for My Morning Jacket during their East Coast leg, which put them on the modern rock radar and launched a 10-year-long process of gaining recognition and acclaim.

Early in their set at The Catalyst, the band launched into two tracks from their new album, including the poppy single “Broken Heart,” sung by bassist Toby Leaman, and a funky ode to uncertainty, “Love,” at which point the rowdy crowd began cheering.

Standing beside a flashing neon light that read: “Dr. Dog — Live from Steamer Lane,” lead guitarist and one of two main vocalists Scott McMicken — donning his iconic floppy fedora — held his gaze steady on the crowd. After he played some wilder songs to open the set, McMicken quietly began singing the opening lines to “Shadow People,” a staple off their 2010 gem “Shame, Shame.” As the song reached its crescendo, every member on stage began to dance in unison.

When the song came flooding through the room, I stood up from my table and drifted toward the dance floor. Trudging through the crowd, I finally peeked my head above the wave of bodies to find McMicken strumming chord after chord, each one rattling my head. I smiled uncontrollably.

The majority of the audience was relatively young, — many under 30 years old — and Dr. Dog’s string of summery tunes moved them to bob, shake, twist, shout and flail about, always moving with the beat of each song.

Near the middle of the set, the band shifted toward one of their more down-tempo songs, titled “The Truth,” the opening track on “B-Room.” The crowd, easing into the slow-burning anthem, slowly began wobbling back and forth. As the song built toward a climax, McMicken began repeating the lines, “Let the rain fall,” while the audience took up his chant. The whole room began vibrating and pulsating — a palpable sense of energy weaving through the audience.

Afterward, in the misty evening light, the rain started to fall. The crowds drunkenly spilled out of the warm and smoky Catalyst, with crooked faces and slurred speech, while Dr. Dog packed up their gear and drove to San Francisco, their sweat-creased foreheads drying up, headed for the next night’s party.