Loco has a duration of roughly 8 minutes and is composed in a single movement. Higdon described her inspiration for the piece in the score program notes, writing:
"Loco" celebrates the Centennial season of Ravinia, and the train that accompanies the orchestra. When thinking about what kind of piece to write, I saw in my imagination a locomotive. And in a truly ironic move for a composer, my brain subtracted the word "motive", leaving "loco", which means crazy. Being a composer, this appealed to me, so this piece is about locomotion as crazy movement![1]
Jeremy Eichler of The Boston Globe described Loco as "a gleaming and rambunctious curtain-raiser".[3] Scott Cantrell of The Dallas Morning News similarly called it "seven minutes of high-energy scurries, clatters, chatters, jabs, chugs and fanfares."[4] Andrew Druckenbrod of the Pittsburgh Post-Gazette wrote, "This piece imitates a "fast-moving train," and it roared into the hall. The fanfare-like work filled every nook and cranny with rhythmic pulsing and walls of sound." He added:
The work is less technically descriptive than, say, Arthur Honegger's seminal Pacific 231, but it metaphorically captures the thrill of both being on a powerful train and watching one go by, alternating between both views (complete with wonderful Doppler effect brass calls). It was another intriguing piece by the PSO's composer of the year (Higdon).[5]
