The melody for Op. 17: XXIII is worth picturing in its entirety since all of it is used on Op. 64: IV.
I've actually found the melody from measures three to six in two different Grieg pieces, and I've written about them before. It's in the Symphonic Dances on Norwegian Themes, but it's also in Nineteen Norwegian Folk Tunes, Op. 66: VI. Cow-call and Lullaby:
(notation found here [Op. 64] and here [Op. 66])
Of course, there are some differences, but the melodies are all very similar.
There's more of a resemblance between Op. 17: XXIII and Op. 64: IV than with Op. 66: VI though because the melody in measures eleven to fifteen is similar to the melody in measures eleven to twenty in the section marked B of Op. 64: IV:
I haven't thoroughly studied the fourth Symphonic Dance, but I've listened to it enough to become fairly familiar with it. I'm pretty sure it's in sonata form, and - as occurs with sonata form - these two melodies come back for the second A section.
The B section of the Symphonic Dance shares a melody with Op. 17: XXIV:
When I originally found the melody that Op. 66: VI. and Op. 64: IV have in common, I was reading a book of Grieg's letters. I referenced the index of works in the back and found that, as the opus numbers would suggest, they were written around the same time. The book says the Symphonic Dances, Op. 64 are from 1896, and that the Folk Songs, Op. 66 are from 1896-1898. Again, as the opus number would suggest, the Folk Tunes and Dances, Op. 17 are much earlier; the book says they're from 1870. I think Grieg is pretty well-known for using folk tunes in his music, so I find it interesting that he used the same ones almost thirty years apart.
