I throw better with music than without it....I carry a portable speaker and mp3 player...I keep the volume low enough, so that other groups can not hear it, (outside of 30 feet or so) and turn it off completely when approaching others, whether they are discers or not. Everyone's taste in music is different, so I do NOT assume others like my music, other than the guys I throw with, who I've known for close to 40 years.
I will not use earbuds, because I want to hear what is going on around me. I will not bring my music to a tournament setting, for the reasons mentioned above. Casual rounds only.
On my home course there is a pavilion at Hole 1, and generally a group having a gathering of some sort, and usually REALLY LOUD music playing (especially on the weekends). Sometimes their taste in music does not coincide with mine....I like the Reggae, but hate the Techno Dance stuff....the only holes on the course you don't hear the "pavilion" music, are holes 12 thru 16 which are on the opposite side of the park. When I have MY music with me, I focus better and it helps to override the "pavilion" music.
Out of my last 5 casual rounds, 4 of them we listened to music, 1 we did not. I shot -2, even, +5, -2, and -1. Is it a coincidence my +5 was the round we did not listen to music?
Maybe !! Maybe Not!!