As far as I know, this is the first time Apple has used their new San Francisco family as webfonts. Apple Music is also SF’s first use outside the Watch app/OS/logo and 2015 MacBook keyboard. There are two subfamilies of San Francisco. This is Compact, the narrower version intended for the Watch display. I hope they’ll continue to use SF Compact for stuff like this because they own it — making it much more distinctive than Myriad. It’s also more interesting than the standard San Francisco family, which departs less from the Helvetica it replaces.