There are several Philadelphia dance companies that perform here only a few times a year, touring the rest of their seasons. So every time Philadanco, Rennie Harris, or Koresh Dance Company opens here, I wonder if Philadelphians realize the treasure that just blipped across their consciousness.

Koresh opened a new piece, Promises I Never Meant to Keep, Friday at the Suzanne Roberts Theatre, and it was a stunner, showing the breadth of the Israeli-influenced modern dance company through a series of vignettes about offhand moments and remarks that become more important over time.

The piece opens with "Wonderful World," to Louis Armstrong's classic song, a gorgeous start that has six women sitting on the stage and blossoming in various formations. Then the men strut in for testosterone-filled steps and tricks, followed by the women, who show they can do the same thing.

A series of duets follows, the loveliest performed by Krista Montrone and Joe Colter, a fluid dance of stretched limbs and deep emotions. One section shows a pair fighting and making up and includes an amusing "tap" dance in bare feet as the man tries to win back his girl. There are voice-overs talking about promises, mostly of love: "My promises were like poems. I meant them, I just couldn't keep them."

The few problems were technical. Dancers moved in and out of pools of light, faces rarely lit. An intermission disrupted the piece's flow. The dance, however, was glorious.

The evening opened with Trails, which Melissa Rector choreographed for her Koresh Youth Ensemble, talented high school students who may be the future of the company.

That future was brought up several times. Rector talked about her students, and artistic director Ronen Koresh spoke about fund-raising on a video loop that played as the audience members settled into their seats. Koresh addressed the audience before the performance about a challenge grant to buy the company's new headquarters on Rittenhouse Square. It was a hard sell but would be worth it if Philadelphia audiences got to see more of Koresh.