Of the 12 major keys, F♯/G♭ is the only one that can be reasonably notated in two ways, since C♭ and C♯ are far more awkward than B and D♭. Both F♯ and G♮ are in common use, but G♭ is rather more common. Why? If the music sticks to the diatonic major scale (as this piece largely does), then both keys are equally complicated, but major-key music often introduces secondary dominants such as V/ii and V/vi (seen in mm. 10 and 16 of this piece respectively) that are written with naturals in G♭ but would require double sharps in F♯. It is slightly more unusual to see the brief modal mixture that shows up in the score as double flats. So the key choice is a toss-up, and Dvorak chose the slightly more familiar G♭.

As for the resultant mismatch with the middle section, pianists are used to seeing enharmonic key changes when moving to the parallel minor (e.g. the D♭ maj-C♯ min shift in Chopin's 3rd Scherzo, Fantaisie-Impromptu and the "Raindrop" Prelude).

Of the 12 major keys, F♯/G♭ is the only one that can be reasonably notated in two ways (for example, C♭ and C♯ are far more awkward than B and D♭). Both F♯ and G♭ are in common use, but G♭ is rather more common. Why? If the music sticks to the diatonic major scale (as this piece largely does), then both keys are equally complicated, but major-key music often introduces secondary dominants such as V/ii and V/vi (seen in mm. 10 and 16 of this piece respectively) that are written with naturals in G♭ but would require double sharps in F♯. It is slightly more unusual to see the brief modal mixture that shows up in the score as double flats. So the key choice is a toss-up, and Dvorak chose the slightly more familiar G♭.

As for the resultant mismatch with the middle section, pianists are used to seeing enharmonic key changes when moving to the parallel minor (e.g. the D♭ maj-C♯ min shift in Chopin's 3rd Scherzo, Fantaisie-Impromptu and the "Raindrop" Prelude).

Of the 12 major keys, F#/Gb is the only one that can be reasonably notated in two ways, since Cb and C# are far more awkward than B and Db. Both F# and Gb are in common use, but Gb is rather more common. Why? If the music sticks to the diatonic major scale (as this piece largely does), then both keys are equally complicated, but major-key music often introduces secondary dominants such as V/ii and V/vi (seen in mm. 10 and 16 of this piece respectively) that are written with naturals in Gb but would require double sharps in F#. It is slightly more unusual to see the brief modal mixture that shows up in the score as double flats. So the key choice is a toss-up, and Dvorak chose the slightly more familiar Gb.

As for the resultant mismatch with the middle section, pianists are used to seeing enharmonic key changes when moving to the parallel minor (e.g. the Db maj-C# min shift in Chopin's Fantaisie-Impromptu and the "Raindrop" Prelude).

Of the 12 major keys, F♯/G♭ is the only one that can be reasonably notated in two ways, since C♭ and C♯ are far more awkward than B and D♭. Both F♯ and G♮ are in common use, but G♭ is rather more common. Why? If the music sticks to the diatonic major scale (as this piece largely does), then both keys are equally complicated, but major-key music often introduces secondary dominants such as V/ii and V/vi (seen in mm. 10 and 16 of this piece respectively) that are written with naturals in G♭ but would require double sharps in F♯. It is slightly more unusual to see the brief modal mixture that shows up in the score as double flats. So the key choice is a toss-up, and Dvorak chose the slightly more familiar G♭.

As for the resultant mismatch with the middle section, pianists are used to seeing enharmonic key changes when moving to the parallel minor (e.g. the D♭ maj-C♯ min shift in Chopin's 3rd Scherzo, Fantaisie-Impromptu and the "Raindrop" Prelude).