This should be easy to do. Then I realized I had not yet ripped CD tracks to MP3 files on Linux or Mint. I discovered Sound Juice in the package manager, so I downloaded and installed it. First problem: ripping to MP3 format requires another library called “lame.” So I downloaded and installed it. That got Sound Juice working just fine. Almost.
Turns out there is a defect of some king that prevents Sound Juice from properly ripping multi-disc sets. The problem is described on this page:
This may be fixed in the future, but I needed a solution today. In poking around I noticed that K3b program will rip CDs, in addition to its other functions. And it works! Problem solved.