A. Dvořák: Humoresque 101/7 - Diatonic Analysis

Real sound materials of this piece can be found here.
Again we repeat that for reasonable analysing of this piece it is good to be able to play it from memory first (doesn't apply for music professionals).
Before detailed analysis let's look at the overall structure of the piece: 

We can see that it contains 3 themes. Two of them in Gb scale (major mode), the third one in A. But not in A major, the root is in F#, what is minor mode with the same root as major Gb. It means 'like' the same scale/key but with darker mood. So the scheme is: one root, brighter->darker->brighter again.

Now let's look at the details of Theme 1:

We can see main melody theme beginning with omited 4 and 7 what gives it it's strong pentatonic character. As concerns bass and harmony, nothing extra interesting happens (what is good for understanding) until bar 7, just pure tonic, dominants and predominats. In the last fragment (bars 7, 8) we can see standard section ending tonic-dominant-tonic, but with interesting bass line in contrast with melody line. Bass: mainly the sequence 6 6/5 5, melody: 5 5 1 1 2 5 1.

Theme 2:

In melody line we can see one sub-theme repeated twice (bars 9-12, 13-16). Expectedly the first version is more modest, the second one more expresive. In the bar 16 we can see interesting chromatic ending. In the harmony line we can detect usual 6 2 5 1 progression (see ChiMai analysis). It makes the part 9-12 quite straightforward. Version 13-16 is more complicated at the end, but we can detect usual progression 3 6 2 5 there, that makes tension to continue in tonic, what happens in bar 17 where Theme 1 repeats again.

Bars 17-24, Theme 1 again, everyting repeats until the end - bars 23,24, that is different from ending 7,8:

There is more happening - we can see two more chords accomodated there - 6 & 2, what makes progression 6 2 5 1 (in line with bass) - longer version of natural path home. In melody a bit of chromatics: 5-TT and 3/2-2.

Theme 3:

Here in the first fragment (bars 25, 26) we can see usual bass/harmony minor triad 6 5 4, but in scrambled order ending with mini P4 progression 5 1 (but 1 is not home/root here, root is 6!). In the second fragment the same with accomodated 2 chord, what makes that P4 progression even longer. Third fragment as evolution of first one, the last one ends in (sharpened) 3 that is dominant of the scale (of 6) - creates tension to continue again on 6.

Here we have the whole second version of Theme 3, to see the (quite small) differences. Fragments 2 and 3 are harmonicaly swapped in compare to the first version. The last fragment is again harmonicaly similar to it's peer from first version - creates tendency to go to 6, but(!) the six will become 1 of Gb scale, because the song continues with Theme 1 in bar 41. We will not present it here, everything is motstly repetition. Just the very last fragment - ending:

It is last fragment of Theme 2 variant. We can compare it with bars 15 16, that end the first Theme 2 instance (there were chords 2 5 3 6 2 5), here it is quite modest 2 5 1 5 1.

Summary of all chords: