Lisa wrote to us:
"Second City T.V. did a sketch about an album of songs that only dogs can hear (I'm not sure if the artist was Joni or Joan Baez), and there were songs such as 'Big Yellow Hydrant,' and 'The Last Time I Saw Rover'"
We'll go out on a limb and bet the artist was indeed Joni! Thanks for the tip, Lisa.
(Contributed by Lisa)