Everytime I add a new song to my phone...either from Bluetooth or Download or others,I get them when I check my files. But unfortunately I need to switch off my phone and on again so as to get the new song(s) in the song list in the music player. Why MS don't have an option for this? Or may be I dont know if they have.
Please note : Music player. load only music folder by Default.its not possible to changes. so you need to move all song in music folder both(memory card and phone memory). then try it.
My suggestion is use Perfect music player,its working fine and well, and have option to re-scan all music in your phone.so whenever you can add song just re-scan for get the song and load to player