"Dear Diary" is an original song performed by The Chipettes in The Chipmunks episode Dear Diary and has yet to be released as part of an Alvin and the Chipmunks album.
Lyrics
The Chipettes:
Diary
Secrets that we share
I would never get to say
Things I tell you every day
Dear diary
Under lock and key
You respect my privacy
You are what a best friend ought to be
Keep a secret
When I'm feeling blue
Keep a secret
Ah oh, keep a secret
Saw my dreamboat at the dance tonight
Didn't give me a second look
He would die if he knew what I write
About him in my special book
Dear diary (oh)
Ah oh, keep a secret
Ah oh, keep a secret
Diary