What's a simple & reliable way to transfer & listen to mp3s on my iPhone? Please don't say iTunes.  I've owned countless iPods (including the original) and iPhones (including the original) and iTunes has never been a reliable means for getting content on to an iOS device.

I basically have a bunch of mp3s (~4,000) that I listen to on my desktop &amp; my iOS device.  I regularly run into the "dotted circle" issue, resulting in only some of my music being transferred.

I've searched &amp; tried the various tricks on Stack Exchange, as well as elsewhere on line.  

Specifically:


I've reset my device but this is not practical to do on a regular basis and it hasn't worked.  It results in a different, random subset of my songs being transferred. 
I've tried removing all my music &amp; resyncing.  This doesn't work.  It results in a different, random subset of my songs being transferred. 


At this point, I want to give up on iTunes.

I just want something to get my music on my iOS device &amp; enable me to listen to it.  

I'm not interested in cloud services, despite Apple's push.  I already own most of the music I want to listen to &amp; I'm not into new music.  I already paid for the music I have.  It seems silly to now "rent" it.

I'm fine with not fancy.  I have no need to for fanciness.  I don't care about machine learning, auto playlists, content discovery.  

Again, I just want to transfer &amp; listen to my music.

I'm totally fine if this is requires new apps.  As long as it transfer music &amp; there is a "play" button, I'm happy.

Similar questions from my research (that don't actually help in this case):


Music files don&#39;t copy from iTunes to iPhone, appear grey with a dotted circle
iTunes refuses to copy music to iPad
If you don't use Apple Music I would suggest something like iMazing (satisfied user for over a year) or another iTunes alternative with music management option. 

Another solution is using Infuse or VLC as a player instead of the native Music app, you can import songs with File Sharing in iTunes and it shouldn't be affected with the 'dotted circle' bug.