It all began with a doomed piece of playground equipment and a dirty yogurt tub.

San Francisco-based composer Nathaniel Stookey had more than a passing admiration for the sprawling metal rainbow-colored play structure in Golden Gate Park, where he regularly took his children to play. “While my kids were in there, I started playing on this thing. It had all kinds of different metal panels, and I just kind of worked my way around, playing on it and thinking how much fun it would be to bring a bunch of professional musicians to the playground and do a concert on this play structure.”

But it was not to be. The playground was abruptly renovated to accommodate safety concerns, and the play structure was dismantled.

Around the same time, Stookey visited San Francisco Recycling's Web site to determine whether he needed to rinse a yogurt tub before depositing it in his recycling bin. While unable to find an answer to his query, he did discover SF Recycling's Artist In Residence Program. Traditionally, the program had hosted sculptors, collage makers and other visual artists, but Stookey was convinced garbage could be musical as well.

Stookey briefly entertained visions of unearthing his beloved play structure from the landfill, reassembling it and bringing his original idea to fruition. “This was before realizing that [SF Recycling] is actually a transfer station and that the rainbow play structure probably found its final resting place many miles from the dump where I ended up,” he says, dejectedly.

Instead, Stookey created a motley ensemble using pipes, pans, mixing bowls, bottles, serving trays, deck railings, dresser drawers, oil drums, bike wheels, saws, garbage cans, bathroom fixtures, bird-cages and shopping carts, selecting items primarily for their resonance. To feature the unique instruments, he wrote a three-movement symphony called Junkestra, which premiered on May 25, conducted by Benjamin Shwartz of the San Francisco Symphony and performed by eight members of the symphony's youth orchestra.

Stookey has worked with symphonies around the world and says coaxing melodies from discarded kitchen implements was surprisingly analogous. “It's very percussion driven, but it's completely melodic and harmonic, just like anything I would write for symphony orchestra.”

The challenge, says Stookey, was labeling the pitch of each instrument. Since none of the instruments are tuned to a conventional scale, the notes produced tend to fall between the cracks. As he puts it, “No one B Flat in the Junkestra is the same as B Flat in another instrument in the Junkestra.”

But Stookey says that was just part of the intrigue of the project. “The instruments came in whatever pitches they came in, so the music that I wrote for them very much grew out of the instruments themselves — this kind of natural sound of the dump, if there is such a thing.”