Feedback created by guitars and amplifiers is difficult to use in musicalsettings – parameters such as pitch and loudness are hard to specify preciselyby fretting a string or by holding the guitar near an amplifier. This researchinvestigates methods for controlling the level and pitch of the feedbackproduced by a guitar and amplifier, which are based on incorporatingcorpus-based control into the system. Two parameters are used to define thecontrol parameter space – a simple automatic gain control system to controlthe output level, and a band-pass filter frequency for controlling the pitch ofthe feedback. This control parameter space is mapped to a corpus of soundscreated by these parameters and recorded, and these sounds are analysed usingsoftware created for concatenative synthesis. Following this process, thedescriptors taken from the analysis can be used to select control parametersfrom the feedback system.