Alternatives Software for iTunes on Mac

@joscow  Sorry to hear that.  I have I tunes Version 12.9.5.5 running on late 2014 MacMini with Mojave Version 10.14.6 and have zero problems.  I changed library, but it was long time ago.  There is Itunes media location (Preferences => Advanced) and Library name (Preferences => General).  All my files are under folder Itunes/Itunes Music.  I have marked (Preferences => Advanced)  "Keep Itunes Media Folder Organized" and "copy Files to Itunes Media folder when adding to Library".  When I point to any folder containing music and select File - Add to Library it adds listing to named Library and copies files to "Itunes media location".  You can start new Library with new name and media location and then add any file you want.  

I had dropouts with 2.4GHz but never hanging.  How much memory you have.  Exit programs you don't need.  I hope it will help.
I went thru many versions of OS and few Macs and never had problem with Itunes.

Another vote for Audirvana, it works flawlessly with MacOS, it is really user friendly and it allows to use iTunes Library together with any other that you want create. 

joscow The dropouts may be related to your WiFi. If you are on 2.4 GHz band try to change to a different channel or if you have a dual band router, try 5 GHz.

The freezes and hangups are a different matter. Perhaps you need to reinstall iTunes, or perhaps your iTunes library is corrupted. What version of iTunes are you using and what Mac OS and what are your computer specs. 

I am currently using a 2014 Mac Mini as a music server running Mojave Version 10.14.4 and iTunes Version 12.9.4.94 and have had no problems. For the last 9 years I have had several different Macs running different Mac OS versions and iTunes versions and never had a dropout, hangup or freeze. 

I love Audirvana - and it DOES sound better than iTunes.  But you must own all of the music in your library it it will not play in Audirvana.  This is a problem for me because I pay for Apple Music $15/mo and just add all kinds of whatever I want to my library, but then I can't remember if I "bought it" or not and my library becomes extremely frustrating to navigate, which is a big turn off to me.  So, if I'm in the mood to listen to older music that I know I own, its Audirvana and a joint.  If I'm working and streaming and just background music, its ITunes.  If I whip out the bong then you know I just warmed up my tube pre and am about to spin some vinyl!  

Audirvana has sounded superior to iTunes for years, especially when it started reading the music instead of having iTunes do it. ITunes for the car and maybe during a flight is ok. Try doing anything hires/dsd/mqa thru iTunes, you can’t. 
‘I got rid of audirvana a couple years ago and went with Roon, far superior in the user interface and how it adds tidal title to your library. The sq of Roon was better than audirvana when I switched but I have heard rumors that the new release of audirvana might sound better than Roon. 
Also, if you want quality playback, don’t use an airport express, too many restrictions.