Thanks for the interesting and informative replies, Clark and Jeff! I ordered an $8 USB keyboard from Amazon on Friday: https://www.amazon.com/gp/product/B017LRFVKS/ It arrived this afternoon (Sunday). I immediately pulled off all but 10 of the keys using a large paperclip (which worked great). I tested it out. It worked perfectly. I replaced the space bar with a smaller key so that I could hit the Alt key easily without hitting the space bar. This is a lot cheaper than the Vidami device that inspired me: https://www.amazon.com/Vidami-YouTube-Hands-Video-Controller/dp/B08NXV8Q9Y/ The Vidami seems to be dependent on proprietary software and it is made for working witn YouTube videos. I work with MP3 and MP4 files, mostly with VLC, so I didn't want the Vidami even though it looks pretty cool. It also costs $150, so I saved more than $140 with my $8 solution. The tax on the Vidami would have been more than the total cost of the USB keyboard. It only took about 5 minutes to pull off the unwanted keys. Mike