You must go to this link and watch the singing/howling dogs that were featured on Rachel Maddow's show tonight. There are additional clips that weren't shown on her show. They are all well worth watching - you'll howl with delight.
It was particularly interesting to me that more than one dog howled when hearing the theme song for Empire Carpets - and one responded to the Colbert Report's theme song!
Interestingly, our dog Diva slept through the entire panoply of howling dogs. Apparently howling means nothing to a pit bull terrier.
Baxter, on the other hand, was seriously freaked out and after looking around in horror, had to leave the room.
You can watch them here.