[KHS]

You might take a look at MuseScore. It's open source and has a very helpful community.
https://musescore.org/en/node/301061
https://musescore.org/en/project/chord-i...sescore-23
https://musescore.org/en/project/chord-i...ore-3-port

MuseScore is great, but don't expect too much from those automatic recognition features.

Thanks so much! I just downloaded MuseScore 3 yesterday and will definitely explore those plug-ins once I figure out the basic program! I realize it's often a tricky thing to calculate a chord, but even a poor result will save me a lot of work and possibly add some new songs that I've owned for decades to my repertoire.