Coming from Windows Phone to a Pixel 2:
First off, trying to transfer music is difficult. I found a way to do it using the AT&T Mobile Transfer app. All my music, along with all my photos, were transferred to the AT&T Mobile Transfer folder on the Pixel 2. The music was sorted into each album, or by artist. Just everything thrown in there. I've had to manually create, using the ES File Manager app, all my artist and album directories in the Music folder, and then manually move the files to the newly-created directories.
But I digress...
I tried using Neutron (thanks for the suggestion), but I don't see a way to point it to the proper directory. I also don't see any way of downloading album cover art (those didn't transfer properly using the ATT Mobile Transfer app). Neutron does, however, play .WMA files, so that a big plus. Many of the other players - Pi, e.g. - don't.
PowerAmp, on the other hand, seems able to do all of the above, and it's pretty easy to figure out. So I recommend PowerAmp to any people coming over from Windows Phone.