As a practicing musician so far I think he is right; music is a surprisingly difficult subject; in some areas (e.g. Bach chorales) there was astonishing progress in the last 20 years, in others none at all.
for a null hypothesis: Obama (born 1961) would have been 12 years old in 1973, for the release of both <i>Pat Garrett & Billy the Kid</i> (RIAA Gold) and <i>Dylan</i> (RIAA, ARIA, and BPI Gold)<p>see <a href="https://www.gocomics.com/tomthedancingbug/2007/06/16" rel="nofollow noreferrer">https://www.gocomics.com/tomthedancingbug/2007/06/16</a>