Ive been told, for what thats worth, that Apple is splitting i-Tunes into three different apps. Those three apps should work as they do now, i.e. Music app does what the music portion of i-Tunes does now. A new picture app that supposedly will work as the pictures part of i-Tunes does, and so on.
Do you play it through a regular stereo system or small speakers connected to your computer or perhaps headphone or earplug speakers? I ask because I prefer to play music using original, full-size files (as opposed to MP3 files) through my regular stereo system, as that combination provides the best fidelity I've got. I don't know what kind of files are used on YouTube but if I had to bet it would be that they aren't the full-size files on audio CDs.
I'm sure they are MP3, but they are plenty good enough for my hearing aids. I have some excellent speakers connected to my computer, including a subwoofer, and I generally prefer music through that system over my living room McIntosh and Klipsch system.
I know your query was to Jim but I'll chime in. I have two "listening environments": a music/home theater system in the family room and the sound system in the computer room.
The system in the computer room consists of an old Pioneer receiver (retired to this duty because the rear surround channels stopped working) connected to the computer via the headphone out, playing through an old pair of Polk bookshelf speakers. This serves as my computer sound system and doubles as a "media digitizing" platform via a USB SoundBlaster adapter. This is where I digitize LP's using a very old Linn turntable.
The home theater system consists of an Onkyo TX-NR818 receiver playing through a pair of Klipsch Icon fronts, a pair of old Bose indoor/outdoor speakers hanging from the ceiling that I use for rears and a brand new Klipsch subwoofer (the old Velodyne died last week). The Onkyo receiver does not have built-in wifi so I use a USB wifi adapter to get it on the home wifi network.
Regarding music file formats, MP3 is fine if you use a high enough sampling rate when creating them. This is one reason I prefer to create my own music files directly from CD's and other sources. I can control the quality of the content instead of taking whatever lowest-common-denominator format a streaming source offers.
I moved the music I had in ITunes to Google Music. ITunes just got to be more of a hassle than I was willing to deal with, the only thing I use it for is syncing my IPad photos with my IMac. I hope they don't take that away.
I have had the impression that we will still be able to retain our existing library of music that we have purchased, imported into iTunes, etc., etc., and that this will still be somewhat separate from the fee-based streaming service currently called "Apple Music." I think Apple realizes that people who have lovingly built up and nurtured a large iTunes library through the years would rise up in revolt if that were suddenly snatched away from them. I think we'll still have our iTunes library with our playlists and number of plays, sortable by composer, artist, etc. This is what I'm hoping, anyway! I am not interested in streaming music, I have a lot of my CDs imported into my iTunes library plus I have a lot of playlists that I have developed and a lot of albums and songs that I've collected through iTunes over the years. That's an investment in time and money. I am not giving that up!
One thing I AM happy about is that they'll be at last separating out the movies and TV shows, the iBooks and the Podcasts, etc. from the music -- long overdue in my opinion! I am looking forward to that aspect of this. I don't have a whole lot of video on my computer and iOS devices, but a fair number.... I also like the idea of handling backups and such through Finder in the future, too.
This is all going to happen with the release of Catalina, which probably will be in mid-to late September.