Why don't some downloaded songs with edited tags play?

A

AC Question

I often download music to my phone, either through downloaded albums or youtubetomp3. However, occasionally some songs I download online (since they have no tags and just a filename), I cannot seem to edit them without having a playback error on google play music. The majority (say 80%) of songs, I download of youtube, I can edit tags (artist name, song name, etc...) fine and play them. However, some songs, regardless if flac or mp3, and whatever version of mp3 I try to change them with (i.e. mp3tag) and any tagging software, when I put them on my phone, I still get a playback error.

In the end, I have a massive library of songs, the majority which can be filtered by artist name, and the remaining 15% or so, which only shows the song name and I have a plethora of songs labelled under (unknown artist). Is there any work around to this, perhaps copy protection on songs (however, some songs which I doubt have copy protection, even homemade stuff, doesnt seem to work)

Been trying to tackle this issue for some time, any advice would be much appreciated!