Chapter 5 focuses on the previously undiscussed types of modulation pedals. These pedals are all fundamentally driven by oscillation and are time based. This chapter takes a deep dive into the history, technical details, and characteristics of these pedals. Challenges and uses are also discussed. Various examples are given to show how these pedals can be used effective in both conventional and unconventional musical environments. THis chapter will be a great resource for anyone interested in using chorus pedals, phasers, flangers, ring modulators, auto-wah, and more.