Lyrics and Poetry: Not Exactly the Same Thing

I have just found your blog via Dani Jones's clever article which stopped me looking for an illustrator, but now I have another question which you may or may not be able to answer.
I am a music teacher and work a lot with early years, mums and babies, and pre-schoolers, in Scotland. I have a few ideas that I usually put into song rather than write them down but I think they could maybe work as rhyming picture books.
The question is, if I have a good tune that makes a book fun to sing as well as say, is there are place for notation (or even a suggestion that this should be sung rather than said) in a children's picture book? I know that Julia Donaldson has done this with The Snail and the Whale, but I don't know how recommended it is, if you are not Julia Donaldson, and haven't already written The Gruffalo.

Once upon a time, music was part of every educated child's upbringing, because with no TV or video games or children's books, evenings were really, really dull. And music continued to be a part of most children's upbringings for several decades past that time.

But no more. Most young parents today do not know how to read music. That's your answer.

Do you know of any publishers who are particularly into fusing song and poetry?

No.

Sometimes the tune is what makes the rhyme work. Does that mean I haven't written the rhyme well enough?!

Yes.

Ahem, I mean: Perhaps that's subjective. Lots of lovely songs which I personally enjoy have lyrics which only work with the music and particular expression of the singer. That doesn't make those lyrics bad.
But if you mean, does that make those lyrics a bad text for a picture book, the answer is yes. They may be good lyrics, but they're bad poetry.

I suppose it should be able to stand on it's own, like a very good leonard cohen song, as a spoken poem/story, and if/when you happen to hear it sung it's a separately effective experience.
Ultimately, is it better, as with illustrators, to leave such ideas out of initial manuscripts when you send them?

I'm afraid so. Sorry.
Of course, we're all looking toward the digital book revolution, and once that happens, it will be much easier to combine recorded music with illustrations. And then your lyrics can remain lyrics. So perhaps you only need to let it wait a few years.