This is a wild guess, but could be the case for you seeing as the page's name was "Rock Music Community":
Many years ago, when FB went through one of their conversions of "old data" to "new data" -- your old FB profile's data was probably converted. For example if you had a FB account from its college days say in 2005, and in the "hobbies/interests" section you put "Rock music", at one point when FB converted those fields into FB page likes for you automatically, it tried to search for the closest match to "Rock music" and ended up on some random "Rock Music Community" page. I know this was the case for me for a few things and I went and unliked them manually.
Many years ago, when FB went through one of their conversions of "old data" to "new data" -- your old FB profile's data was probably converted. For example if you had a FB account from its college days say in 2005, and in the "hobbies/interests" section you put "Rock music", at one point when FB converted those fields into FB page likes for you automatically, it tried to search for the closest match to "Rock music" and ended up on some random "Rock Music Community" page. I know this was the case for me for a few things and I went and unliked them manually.
Check out https://www.facebook.com/[yourfbname]/likes and see if you find more similar pages being liked by you.