In this assignment, students implement some simple filters on sound objects, including reversing a sound, mixing arbitrary-length lists of sounds, and changing volumes of sounds. These functions can each be written in ten or fifteen lines of code, using objects that represent sounds and samples from our media module. Then, calling on these functions, students write a "song generator": a function that takes a string of note data (a notestring) and produces its representative sound object that can be played or saved as a wav file.