The piano diplomas of senior universities here are not a series of national academic certificates, but professional skills certificates with seals issued by some schools. According to the meaning of the question, the last graduate is the piano skill certificate, not the diploma. These two concepts are different.

Distinguish between schools and educational institutions:

There are also differences between "schools" and "other educational institutions".

"School" refers to an educational institution approved or registered by the government or the administrative department of education according to law, which mainly implements academic education at all stages within the academic system, including primary schools, junior middle schools, senior middle schools, various vocational schools, technical schools, general secondary specialized schools, general colleges and universities and various adult education schools with qualifications for issuing academic certificates.

"Other educational institutions" refers to educational institutions that have been approved or registered by the administrative department of education or other competent departments to carry out non-academic education.