This boxer is howling at a siren, which is what my first dog used to do.
When I was very small we had a Cocker Spaniel that howled at fire engines. Or at least I thought he was a Cocker.

Boxers are another breed who seem to have a lot of good singers. The other breed that I've noticed which sings real well are Huskies. I don't know, maybe it's me, but that's what I think.
What do you think? Do you think other breeds sing as well or better?
Write in and let us know.