This paper examines two of the most common signal processing techniques, namely, equalisation and dynamics processing. As with all signal processing techniques, equalisation and dynamics processing modify audio signals in particular ways to suit the evolving requirements of a mix. Rock and electronica records currently feature the most extroverted uses for these techniques and, thus, the clearest examples for a field guide like this. It is for this reason, and this reason alone, that I focus on records from these two genres. I begin this field guide by suggesting a definition for ‘signal processing’ which is sufficiently broad to account for every technique that recordists currently use. I then relate that definition to the concept of ‘frequency response’. In my opinion, this concept is crucial to any understanding of signal processing – a core component of the knowledge base for audio engineering, which is the discipline under which signal processing is typically subsumed; the concept of ‘frequency response’ guides many of the decisions about signal processing that recordists make, especially those concerning equalisation. Finally, I explain how equalisation and dynamics processing work, and I offer a field guide to their most common applications on hit rock and electronica records today.