Yoko Kanno wrote a commercial song for the Japanese tobacco company JT.
Performed in gibberish by a singer named Caroline, the beautiful 2:05 piano song is available for listening on the Grand Func Inc. official website. I could not find any information concerning the singer though.
The commercial entitled「ありがとう。」(“Thank you”) can be watched on the JT official website.
The full music is available on the Piano Inc. sounds page.