Q: 2015 MacBook crashes when I use the backward button on iTunes?

Hey! I have the gold Macbook from early 2015, 1.1GHz Intel Core M and 8GB RAM. Every time I'm playing a song on iTunes, and use the "back" keyboard key (above the number 8), iTunes stalls for a couple seconds, then causes my laptop to crash and restart. However, this does not happen when I use its sister keys- pause and forward; they function  like they are supposed to. I previously had OS X El Capitan, and it happened on there. After updating to Mac OS Sierra, I was hoping this would be fixed, but it still crashes my computer, leading me to think that it's a problem with my laptop. Any input is greatly appreciated!