i need an easy way to "update my local music copy" on each device. (folders and mp3 files, some txt files)
is there a better way than use SVN for this? can someone recommend a software for this maybe?
SVN or any other VCS tool is the worst choice for syncing remote copies of anything. Just because it's versioning tool, not backup or cloud storage
Any cloud solution for files will be more easy, more natural and more effective way of solving your problem (OneDrive, GoogleDrive, DropBox, ...)
Nextcloud puts your data at your fingertips, under your control. Store your documents, calendar, contacts and photos on a server at home, at one of our providers or in a data center you trust.
This introduction page should help to get a first impression about what it is all about.