Complex sentence: She explained that it was the one song that electronic music duo Matmos helped her with--they did "fruit-machine-noises" that are in the choruses with synthesizers that she later imitated with her voice.
Split into simpler sentences: She explained that it was the one song that Matmos helped her with--they did "fruit-machine-noises" that are in the choruses. He made the noises with synthesizers that she later imitated with her voice.