Over the years I have tried using iTunes to change my music format from m4a to mp3. It did not work and all it has done is to replicate all my music once or twice. That's a lot of storage!
To find and remove all duplicates search the following in File Explorer:
~"*(2).mp3"These searches will find only duplicated m4a (iTunes format) and mp3 songs that have a (2) at the end of the file name. If you have three copies of each song, add a 3 in the brackets etc. You can then select all (press ctrl and A) then delete them.
2. Remove songs from iPad
Since I don't use the music anyway, I thought I would delete it from my iPad. Connect the iPad into the computer, open up iTunes then click the small phone icon that appears. Under the Options heading, untick all the boxes.
You may also need to delete the songs from the device itself. If you do, click Settings on the iPad then click Storage & iCloud Usage. Click Manage Storage under the Storage heading and wait for it to finish adding everything that takes up memory on your device. When it is finished, click Music, then All Music, then Delete.
3. Remove songs from iTunes
I wanted to remove the songs from iTunes so I wouldn't have it reconverting them any time soon.
In iTunes under the Library heading, click Songs. Select all and click Delete From Library. The following warning sign pops up. Personally, I kept the files so I could convert them to mp3 format.
Any songs that are left will be from the iCloud Library and these can be hidden if you want by selecting all and clicking Delete From Library, a second time. Any empty music folders can be deleted by searching iTunes in the File Explorer. Then click Music and you should be able to view all the folders. Select all and click Delete to remove them or leave them if you want to convert them.
4. Convert files to mp3
I downloaded a free m4a to mp3 converter. After it had installed, I clicked File then Add Folders. When all the music folders had uploaded, under the heading Output Format (bottom right hand side), I clicked Setup then General. I ticked the final box- Remove the source file after a successful conversion- to stop further duplication. I then clicked Convert to start the process. It took hours (maybe like 6h to do ~60GB of music) but it worked and it put everything in the correct folders.
Although it took quite a few hours, this was the most hands off approach for me to dedupe and reformat all of my music. Now to factory reset and start again!