Does Pandora not have licensing for some music?

I decided to make up a station of the stuff I used to listen to in high school for my morning in the office: Aerosmith, Led Zeppelin, Ted Nugent, Van Halen, AC/DC and Jethro Tull.

Well, my channel has been playing an hour or so and has only played one Aerosmith track, one Van Halen, FOUR Scorpions tracks, Four GNR tracks, but NO Led Zep, Jethro Tull, or Jethro Tull.

I've had great luck with playing genres or music, such as "Blues", but this selection seems strange on their part to keep playing bands that I haven't selected, while totally ignoring bands that I DID choose when creating the channel.

Is it possible that Pandora simply doesn't have licensing for some bands or something?

(Now it's playing a Blues track even though I've verified I'm still on the Aerosmith Radio choice...(!!!)


::::::: No disrespect to Axiom, but my favorite woofer is my yellow lab :::::::