In Nintendogs + Cats, it can be bought from the BARC shop for $30 once it has been unlocked with 8,200 Owner Points or by playing 27 days. It was renamed "Up In The Clouds" record and it now has a different tune to it.
DS: "Composed by an unknown, this is one of six mystical records that evoke nature."
3DS: "Music to ease your furry pals into a nice nap. So sleepy...zzz..."
This can be sold for $9 in DS versions; $15 in 3DS versions.
This beautiful song makes your cute puppies sleep. You can start all over again to make the dogs sleep longer. After you stop playing the music, they will wake up from their nap and play. This will make their mind fresh and clean.