Harmonic Analysis Chopin op 25 n 1

[aspnet]

Hello,

I am studying the 1st chopin's etude of the opus 25. I have never did harmonic analysis studies and I decided to learn a bit more about it so I read the Piston manual but still I have some difficulties in analysing some passages. I hope you can help me )))))

In measure 5 (sorry I do not have a screenshoot) I have the Ab chord and thus we are on I degree.... then Chopin introduce the E natural and it goes to Dflat on the following chord. How this passage should be analysed harmonically? I I(agumented 5th) IV ? Or the E natural is just a note that does not affect the harmony?

Thanks a lot for your help....

[bobert]

Yes, I, I+, IV.  The augmented chord here functions as a passing chord to IV.  The E-natural adds a second leading tone, resolving to the third of the Db chord (E -> F, the other leading tone being C -> Db), making the transition to IV all the smoother.

[aspnet]

Thanks a lot!!!!