The term 'Certain Calf Brusher' is a job description for someone who uses a MIDI device. MIDI stands for Musical Instrument Digital Interface and is a technology that allows electronic musical instruments to communicate with each other. MIDI devices are used to create, record, and edit music. A Certain Calf Brusher is someone who is responsible for using a MIDI device to brush up the sound of a calf's voice. This job requires a great deal of skill and knowledge in order to produce the desired sound.