I got my HTC One M8. Loved it, but after plugged in my SD card with all my previous music files, most of the albums are split because some songs in the same album has different artists. It was working fine before with Note. I spent a lot of time trying to search for solutions. I tried MP3dit like others suggested, but it did not work. Tried a few MP3 tag editors but none of them worked. Finally ID3Fixer worked for me, with a trick. I used "By Album" option. After "Fix it!" clicked, make sure select the option "Fix Android database only, does not affect the music files" is selected. I tried the default behavior of the other option "Fix tags in music files permanently, please make sure you selecting the right charset.", which is default option, actually did NOT work!
Another good thing about this tool is that during album selections for fix, the ones which need to be fixed are actually sorted on top, out of order in alphabet. So, it's pretty easy to identify what need to be fixed. Hope this will work for you too.
Another good thing about this tool is that during album selections for fix, the ones which need to be fixed are actually sorted on top, out of order in alphabet. So, it's pretty easy to identify what need to be fixed. Hope this will work for you too.