I have a music directory under Nexus 5 which is a git-annex repository. If I sync the same with remote repository, newly added songs or modified songs(modifed id3 tags) will not sync with music player. But if I use Android File Transfer to transfer songs, it will sync music player. The songs which are transferred using git-annex will reflect in music player only after restart. Do we have to execute any command which will sync music player.
A workaround for this is using an external app that pings the media scanner to rescan. It's an extra step to remember, but I haven't found it too much of a burden.
I use this one: https://play.google.com/store/apps/details?id=com.addz.mediascanner, but there are at least a dozen to choose from.