There's always someone with a guitar handy isn't there.
33-year-old Anthony Kulkamp Dias was kept conscious during his surgery to remove a tumour in his brain by doctors in Brazil because they wanted to monitor his brain function in real time.
According to a spokesperson from the Nossa Senhora da Conceição hospital in Santa Catarina "Cerebral monitoring - important to prevent injuries that occur in the sensory, motor and speech areas - occurred during the procedure". This lets doctors make sure that they haven't impaired any brain functions and usually involves patients responding to questions or making conversation.
Kukamp however, who plays guitar professionally, was able to play six songs during his surgery, one of which was 'Yesterday' by The Beatles while doctors worked on removing his brain tumour.