What you see is what you get. Unless it’s not. Case in point: Taylor Hawkins and The Coattail Riders’ appearance on Jimmy Kimmel Live Tuesday. On the air, you saw the Foo Fighters’ drummer and his solo band deliver a swaggering version of their retro-glam number Middle Child — with Hawkins’ boss and bandmate Dave Grohl manning the kit. What you didn’t see on your flatscreen, however, was the online-only bonus track: An equally retro-rocking romp through I Really Blew It, also featuring Jane’s Addiction frontman Perry Farrell. And it doesn’t stop there. While that was all you got for late-night TV music on Tuesday night, (it was guest-chef night on most of the other programs — do they co-ordinate this stuff or what?), that’s not all there is to be had today. Popster Rex Orange Country will be on The Ellen DeGeneres Show today to sing Face to Face, and since Ellen’s people post their clips before airtime, it seems fair to include it here — especially since Rex also performed an online-only rendition of Loving Is Easy. That should be all you get today. Unless it’s not.