Pops concerts are generally cash-flow ploys first and artistic endeavors second. Orchestras seeking economic viability feature them during their regular season because it is impossible, given the arts funding conundrums of the 21st century, to pay for the upkeep of a huge musical force by confining concert programming to “masterworks” of the classical repertoire.

Given this particular set of circumstances, the mandate for combining entertainment with musical quality is most important. People won’t come and fill the seats if they don’t think they’ll get their money’s worth.

That’s why Saturday’s BPO concert in Kleinhans Music Hall was such a welcome surprise. A couple of things could have prevented the show from coming off. The lineup of singers kept mutating almost until the final moment, and Ron Spiegelman, the BPO’s former associate conductor and the scheduled leader of the band for the evening, was stuck in Springfield, Mo., because of the weather.

Luckily, the choice of singers – Katie Rose Clarke and Julie Reiber – was finally settled, and Erin Freeman, who came to Buffalo to rehearse the BPO Chorus for a March performance of Handel’s “Messiah,” was available to fill in for Spiegelman.

To top it off, everything came together. Freeman’s conducting was kinetic yet focused, the singers were personable and talented, and the orchestra responded in kind.

Given that the theme of the evening was “Wicked Divas,” it was necessary to find a couple of singers whose resumes included stints in “Wicked,” the musical twist on Frank L. Baum’s “Wizard of Oz.” Clarke and Reiber, who played Glinda and Elphaba on Broadway, were perfect choices. That they were able to carry off the mix of material drawn from other Broadway shows, the stuff that made up the bulk of Saturday night’s performance, was no fluke either.

While Clarke and Reiber inhabited their roles – Clarke’s “I Could Have Danced All Night” and Reiber’s “Ring Them Bells” were early standouts – the orchestral sections were played with plenty of verve as well.

The BPO began with the overture to “Gypsy” and then whipped into a few instrumental selections from Georges Bizet’s “Carmen” that got a favorable response from the audience. If there was a quibble to be had, it was something that most large orchestras have trouble with – being nimble in quick-paced pop songs. “Conga,” a riff that originally topped the charts in a version by the Miami Sound Machine and the vocal flexibility of Gloria Estefan, didn’t translate over to the string section arrangement that was doubling her lines.

When Freeman got the audience to respond to cues with the kind of hand gestures that the Supremes were coached to do in “I Hear a Symphony,” the results were fun to follow, despite the lack of precision that Motown’s choreographer Cholly Atkins was able to get out of Diana Ross and her cohorts during rehearsals in the record label’s famous Studio B.

Still, it was an evening of fun that came off despite all odds. Kudos to all concerned.