My comment:
(a) "低調曝光." I do not know what it means. What I can find is as follows.
(i) The only news about this topic is two of today, both in in Chinese: first is from Radio Free China and then from 法广 (which cited RFA and 聯合報). Nothing from news media within China or in English.
(ii) I fail to find comments or video in the Web, except
著名二胡演奏家江泽民先生精彩演奏！ YouTube, published by "Xi Gou" on Apr 22, 2017. https://www.youtube.com/watch?v=y_mvg-mUChg
(b) Take notice that in this video, fingers of Mr Jiang Zemin is not as fast as the male and female 二胡 players in the background. Besides, Jiang appeared to repeat the same hand movements again and again -- leaving me wonder whether he was really good at it.
(c) As the 聯合報 report explains, there is in the Web another 江泽民 二胡 video "二0一五年 * * * 中秋節一小型公開場合拉奏胡琴(視頻直到次年秋天才對外曝光)."