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.