Hi all, My cousin has emailed me a couple of songs on Mp3 he has done on acoustic guitar/vocals. He has asked me to put a bass line to them. I have very little knowledge of how to do this. I have Audacity downloaded on the my laptop and have used this previously to change pitch on songs I have had to learn. I have a TC electronics RH750 amp which has a digital out socket. What cable will I need to record on to Audacity, I have downloaded the Mp3 track to Audacity. My laptop is a HP Pavillion running Windows 10. Will I need to plug in to a USB socket or Mic/Headphone socket on laptop. Any other advice would be appreciated, cheers.