Four Year Strong performs at the Botton of the Hill in San Francisco on Jan. 10, 2019. Photos: Sean Liming.

SAN FRANCISCO — One half of Massachusetts melodic hardcore rock band Four Year Strong kicked off a limited run of stripped-back shows at Bottom of the Hill on Thursday. The 10-show tour, which even included some songs performed completely acoustically, will cross the U.S. back to the band’s home state.

Singer-guitarists Alan Day and Dan O’Conner brought an MTV-Unplugged-like session to the stage, and it was an unusual sight for suck heavy rockers, who were playing acoustically for the first time, which O’Conner acknowledged made him nervous.

While the punk feel of the chords and lyrics begged for electric sound. But delivered softly, it also felt more organic. The 12 song-set, beginning with “Go Down in History.” Between songs, the temporary duo talked about listening to fan conversations and reactions, made possible by the quieter atmosphere and easy-flowing vibe, which made the performance more memorable to them. During one of the quiet moments, the band could even hear a fan yelling to ask for beard-growing advice.

“Ask your dad,” O’Conner quipped.

Day,  meanwhile, talked about how the two locked themselves in a garage for two weeks to nail down the new arrangements, joking that he was afraid of losing his wife during that time.

The show went off without a hitch and the set included “It Must Really Suck to be Four Year Strong,” “Nice to Know,” “We All Float Down Here,” “Finding My Way Back” and “Heroes Get Remembered, Legends Never Die.”

The tour continues tonight at the Constellation Room in Santa Ana.

Hot Mulligan preceded the headliners, feeding off concertgoers’ energy. Singer Chris Freeman narrated the back story of each of the band’s songs, going guitarist Tades Sanville a chance to ramp himself for the songs. The pop-punk’s band’s best-known tune, “All You Wanted By Michelle Branch” (that’s the actual name; it’s not a cover) got fans singing along.

A couple of songs later, Freeman requested fans to start stage-diving; only to be reminded by club managers that this was not allowed at Bottom of the Hill. Hot Mulligan finished its set with “How Do You Know It’s Not Armadillo Shells?”

Pleasant Hill natives Elder Brother (The Story So Far guitarist-singer Kevin Geyer and Daybreaker singer Dan Rose) eased into its set joking about the time it took the duo to get through Bay Bridge traffic (if you’re reading this and not familiar with the Bay Area, just take them at heir word). The band’s smooth melodies enraptured fans for during a six-song, 15-minute set including “Wish You Were Here,” “No Reason” and “Carry You Home.”

Cory Wells opened the show with a short set of heartfelt songs about love and heartbreak, including “Damage” and an as-yet-unrelased tune called “Patience,” before ending with “The End of a Good Thing.”

Follow photographer Sean Liming at Twitter.com/SeanLiming and Instagram.com/S.Liming.