Why does it matter whether or not it’s recognized?
Nobody sees your diploma - it’s not like you show it to employers or others to get jobs or positions. At best, you’ll hang it on your wall. But if your major concern is keeping up with your music, taking classes/lessons, playing at a high level, having high-level teachers and peers and a good ensemble - whether or not you can formally declare it as a concentration doesn’t really matter as long as the other elements are there.