Tomorrow lies in the cradle
Tomorrow has eyes that shine
Tomorrow lies in the cradle
With a smile that shows how little I know.
- Fred Hellerman, "Tomorrow Lies in the Cradle" (The Weavers, Together Again, Loom Records, copyright 1981)

Fannish or not, we're all encouraged to sing to our children.  And kids love music, whether their parents can carry a tune or not.

In our house, there are three adult filkers (some more active than others), all of whom were encouraged to sing as children, and all of whom love to sing to the children. And all of us encountered song parodies, such as this one, before we'd ever heard of filk.

On top of spaghetti
All covered with cheese
I lost my poor meatball
When somebody sneezed.
It rolled off the table,
It rolled to the floor,
And then my poor meatball
Rolled out of the door.
- Tom Glazer, "On Top of Spaghetti" (to the tune of the traditional ballad "On Top of Old Smoky," copyright 1963)

But even before I learned that song, I remember triumphantly announcing to my Dad that "Twinkle Twinkle Little Star," "Baa Baa Black Sheep," and the Alphabet Song all had the same tune!  I soon started seeking out songs which shared tunes.  As I grew older and began taking jazz lessons, I delighted in learning about variations on tunes and chords, learning to improvise.  My husband Wolf and I sing a blues lullaby to our children, with improvisation, adding words as we feel like it.  It's a huge amount of fun.

Hey little baby
Hey little baby
That's you
Hey little baby
Doot doot doot doot doot dee do deedee do.
Doot doot doot doot doot dee do deedee do.
- Jacob Sommer, "Hey Little Baby" (copyright 2005)

Another favorite for improvisation is the wonderful "Mah Nà Mah Nà" song, as done by Jim Henson's Muppets.  Singing it with silly voices kept the Tiger Kitten entertained for a good fifteen minutes this morning.

There are wonderful silly songs and sweet songs everywhere that can be sung to children.  You can sing whatever songs come into your heads, as long as you don't mind having to sing it over and over again, or hearing your child do the same.  I've caught myself humming the theme to Robot Chicken (decidedly inappropriate for children under 16 - or 32) to the kids more than once.  Many kids love scary songs, too.

Close your eyes and sleep
There are demons in your dreams
Go to sleep my darling
there's a demon underneath your bed
Demons in your bed
are going to eat you up
- Daniel Glasser, "Close Your Eyes" (copyright 2003)

Of course, not everyone grew up with songs and music around them.  There are some amazing resources for parents who are timid (or not) about singing with their children.  The Wolf Cub and I love Music Together, a music and movement program for children aged 6 months to 3 years, available all over the United States.  There are theater groups and after-school programs available nearly everywhere (check your local newspaper and public school websites), and one can always pick up a good songbook like Rise Up Singing.  And if worst comes to worst, there are wonderful children's CDs available at your local library.  Just remember, you don't have to stay in the children's section - there are sing-a-long songs in nearly every genre of music.  There are songs like "Yellow Submarine" by the Beatles, or "Little Boxes" by Marina Reynolds. These have the added benefit of having hidden meanings that you can talk about with your children as they grow older.  You can find music that encourages movement - salsa or reggae, for example.  My personal favorite as a child was an album of the Missa Luba, a version of the Latin Mass based on traditional Congolese songs. I still own the LP.

I can blather on and on about ways to sing with your children, but the best way to do it is to just do it.  Listen to and sing songs together, and think of ways to dance and clap to them.  Sing in the car, on walks, while changing diapers.  And do it as early as you can, before they have a chance to get embarrassed about it!

I've listed as many references as I can think of in the links below.  I hope there will be even more in comments.

Happy listening!

Oh, fen, don't let your children grow up to be mundane.
For it's a great mistake, and it will surely cause you pain.
So learn, if you will tarry and hearken unto me,
(Why it's) a fannish obligation to raise fannish progeny.
- Mark A. Mandel, "Fen, Don't Let Your Children Grow Up to be Mundane" (to the tune of "Johnny Be Fair" by Buffy Sainte-Marie, copyright 1999)