Send To requires the phone to be connected by USB and be set to MTP mode ( or equivalent}.

Thanks. I tried to simply manually sync by selecting files and right clicking and doing a send to. But my android phone is not an option in the "send to". This is probably related to the statement in "devices" that while the android is listed there it is "disconnected". I can't figure out how to reconnect it. (And it is connected the other way, since in the android I can start a sync and it's talking to the Windows server over wifi, but I can't do a manual sync (from Windows to android) that way from what I can tell.)

Full Sync guide: https://www.mediamonkey.com/wiki/WebHelp:Exporting_Tracks

You should be able to select files in Folders (which shows all file including those not in your MediaMonkey Library) and Send To > Sync that way. However I meant that you can Sync selected files from your Library and have Auto-Conversion take care of syncing them as MP3's.

Thanks, I did not now that MMW could auto-convert. Is there someplace that describes the settings needed in MMW to get a select group of new files auto-converted and put into MMA?

Alternatively....
Re: Your second comment: [quote]You can do this for manual Sync of selected files as well[/quote]

Since I have the MP3 already, I'm not sure how this manual sync method would work, since the MP3 files are not currently in MMW. How do I have these MP3 files recognized from the Windows machine folder they are in, and brought into MMA on the phone?

Note that MMW can [url=https://www.mediamonkey.com/wiki/WebHelp:Exporting_Tracks#Auto-Conversion]auto-convert on Sync[/url], no need to deal with the hassle of separate copies.

You can do this for manual Sync of selected files as well.

I have a large collection on MMWindows consisting of WAV and FLAC files, and I separately have the entire same collection, but as MP3 files, which are NOT catalogued in MMW, but all are catalogued on the MMA version on the phone.

If I want to add some new MP3 files on the phone, I can't use the sync function in MMA/MMW since that would simply send the WAV or FLAC files to the phone. So, how do I simply download some new MP3 files to the phone, and have MMA add them to the catalogue on the phone.