We present an attachment for the bass guitar which allows MIDI-controlled actuated fretting. This adapted instrument is presented as a potential method of augmenting the bass guitar for those with upper-limb disabilities. We conducted an online survey of 48 bassists in order to highlight the most important aspects of bass playing. We found that timbral and dynamic features related to the plucking hand were most important to the survey respondents. We designed an actuated fretting mechanism to replace the role of the fretting hand in order to preserve plucking hand techniques. We then conducted a performance study in which experienced bassists prepared and performed an accompaniment to a backing track with the adapted bass. The performances highlighted ways in which adapting a fretted string instrument in this way impacts plucking hand technique.