Shadowbox and BalletMet's guest choreographers team up for "7 Deadly Sins."

Choreographer Amy Seiwert was cooking dinner in her San Francisco kitchen when she first heard the adagio of Beethoven's "Moonlight Sonata." "I thought, 'This would be perfect,' " she says. "It's so achingly beautiful in a way that's got a very dark side. It's almost hollow."

Seiwert is one of the visiting choreographers for BalletMet's "7 Deadly Sins," and "Moonlight Sonata" is now being incorporated into music for the Envy section of the performance. The score for the troupe's April show is unique: It's being created and will be performed live by the band of musicians from Shadowbox, the sketch comedy club in Easton.

Seiwert, who was in town last week working on the choreography, sent her idea of adding "Moonlight Sonata" to Envy to Shadowbox's executive producer Stev Guyer. His band took the suggestion and created a score that is "open and haunting," he says.

It begins with a spooky slide guitar "over a simple bass and percussion line. We are then moving into 'Moonlight Sonata' with a piano playing the basic chordal pattern without the arpeggios, and the slide guitar is playing the melody line. As the piece progresses, the guitar becomes an electric, distorted instrument playing the melodic line in more of a Pink Floyd fashion."

As of now, the dancers in Envy will be en pointe, Seiwert says, and the piece infuses the particular awfulness of this transgression. "To me, envy is such a nasty feeling to have," she says. "Lust is sexy; anger you can be justified. There's nothing justifiable about envy. It's such a nasty trait and it makes your belly just kind of sicken."

As for the seven sins' music, Guyer says the groups are using an extremely collaborative process. He conceives the mood and story of the piece, then Shadowbox guitarist Matt Hahn and Guyer create a chord patter and musical structure. Next the band members contribute ideas via individual instruments; lyrics are written and harmonies for voices are created.

But even then the work isn't done.

The artistic process for the music is as complicated as creating the dances. Revisions will come in from the various choreographers; there are suggestions for additions, editing. While this process has its challenges, Seiwert and Guyer agree that the results have been fascinating to observe.

"There's something really wonderful about watching it evolve," Seiwert says.

Guyer adds, "The choreographers don't necessarily see it the same way I see it, so there is another level of compromise and collaboration that must occur for each piece, but, in the end, this only makes the work more interesting."

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