The two shows Chris and Rich Robinson performed in Philadelphia on Friday were as different as night and day — or, chronologically speaking, day and night.

The Georgia siblings formed the Southern rock band Black Crowes in 1984, and by the early 1990s, when grunge and hip-hop were huge, so were the skinny-legged, classic-rock throwbacks, schooled in the Faces and Allman Brothers. They broke up in 2015, with Chris saying of Rich, “We never really had much of a relationship.”

Now, the battling bros are back, plotting a summer Black Crowes tour in celebration of their 1990 debut album Shake Your Moneymaker, which will bring them to the BB&T Pavilion in Camden with new backing musicians on July 14.

First, though, they had a buzz-building tease in store for Philly.

Billed as “Brothers of a Feather,” they initially announced an acoustic show for this past Friday night at the 400-capacity Foundry at the Fillmore. When that sold out, they added a WXPN-FM (88.5) Free at Noon concert at the slightly larger World Cafe Live.

The noon show was short and superb. Alone on stage, the duo opened with Moneymaker’s “Jealous Again,” kicking into a note-perfect, unvarnished, six-song set.

Rich played acoustic guitar, crunching chords and adding slide licks, while Chris sang and blew his harp. Songs that once came across as ersatz now sounded authentic. Chris noted that “Wiser Time,” from 1995′s Amorica, was written when “there wasn’t a lot of wisdom.”

The bros had watched the Sixers at the Wells Fargo Center the night before, and Chris expressed admiration for fans who shouted “Sucks!” during intros of the opposing team, calling it “a level of civic pride I didn’t know about.”

The behavior at the Foundry show Friday night was less to his liking. Presented by WMMR-FM (93.3), it featured double the number of Black Crowes songs — with Chris’ Otis Redding-style staccato vocal on “Thorn in My Pride” among the highlights, plus an encore of Ry Cooder’s version of country singer Carson Robison’s “Boomer’s Story.”

But the atmosphere was testy. Twice, Chris asked for quiet from fans who seemed to be expecting a raucous rock and roll show.

“Show us a little respect,” he pleaded, saying he couldn’t hear himself sing. “... You should pay attention. The vibe is great. But get it together.”

It helped when usually silent Rich spoke up in less confrontational terms. But the din persisted in the barroom.

The show didn’t go off the rails. But it began to feel like an evening to be endured, rather than celebrated. “C’mon, it’s Philly!” one lout bellowed, as if that entitled him to be heard as loudly as the performers he had paid to see.