The Mendelssohn Club of Philadelphia assembled a whale of a mostly British music program on Sunday. It would have been great - had the performances consistently honored the music on levels that it required. As it was, the best news that came out of this season-ending concert at Lutheran Church of the Holy Communion is that two of Philadelphia's world-class composers wrote new pieces. Both were in top form, showing hugely different approaches toward the same text.

They program continued Mendelssohn's mini-commissioning series of pieces written to the word Alleluia in honor of retired artistic director Alan Harler. For Sunday's program, James Primosch and Robert Maggio delivered works that felt completely self contained but are full of ideas that should be continued into larger works.

Primosch's Alleluia on a Ground began with unison vocal lines of such apparent simplicity that they could almost have been Gregorian chants. Yet subtle quirks pointed to a discreet individuality that would never have been heard in music from that world. Many vocal lines had what might be called a hinge note, opening a door into unanticipated but never radical directions. These created a web of contrapuntal writing at home in a religious text setting but going to places specific to Primosch, especially with background and foreground effects

Maggio's just as individualistic Alleluia had more familiar points of references, however distant ones, starting with an ebullient rhythmic foundation that could have been inspired by some Polynesian fertility rite. Of course, any such set-up is going to prompt contrasting, longer-breathed melodies to highlight the propulsion, and Maggio did so with much invention - so much that it's safe to say the composer was carried away in the best possible sense. The energy of the performance began to flag in the piece, right when it should have been hitting some sort of culmination. And that moment was somewhat emblematic of the concert.

Any number of moments in Vaughan Williams' Serenade to Music (led by assistant conductor Ryan Tibbetts) and Britten's "Choral Dances" from the opera Gloriana (led by new artistic director Paul Rardin) had so many faltering moments and mushed textures that the performances were rough outlines of the pieces. That was a particular disappointment to passionate admirers of these works, not often performed in the United States. Piano accompaniment came from a sad little baby grand. The church's sound system buzzed intermittently.

The attractive, songlike Consolation, composed by the group's departing longtime pianist, Don St. Pierre, did reveal what a good depth of sound the Mendelssohn Club can produce. And luckily, Jonathan Dove's The Passing of the Year, the biggest work on the program and written only 16 years ago, did receive a credible performance, partly because the music's big picture was so solidly established that momentary mishaps didn't get too much in the way. Dove is one of those composers who gets more love than respect: There's so much to enjoy on first hearing, will his pieces have much to offer subsequently? With this piece, probably yes.

Among the seven movements, the texts are wide-ranging celebrations of nature, from Emily Dickinson's "Answer July" to William Blake's "Ah, Sun-Flower." Dove used whatever musical means he could think of to translate them to a 21st-century sensibility without the slightest trivialization. My favorite effect was the Blake poem: Closely staggered voices suggested row upon row of sunflowers. But can a concert survive on Dove and a few new short works? If the quality is consistently professional, yes.