Piano Forum

Hi everyone,
I've had this question for some time so I decided to give it a try here to see if I get some answers, since due to the pandemic I'm no longer taking clases.

Here it goes: there are many cases of R.H. chords starting with a semitone interval involving a white and a black key that don't seem playable with fingers 1 and 2.

Examples of this:
- SCRIABIN Etude #5 op 42: bar 24, we have G4#-A4-G5#
- RAVEL Alborada del gracioso: on the middle section of the piece we have A5-A#5-C#6-E6-A6
- RAVEL Ondine: bar 27, we have E5#-F5#-A#-E6#

That's what I remember, but there are so many other cases in music from these composers and also a lot from Liszt.

My approach was usually playing the chord with a fast arpeggio, but I have encountered cases where arpeggios do not sound right at all (my second example will be one of those)... so I started to experiment a little playing the keys of the lower semitone both with the thumb. When the white key is lower than the black, I put my thumb in a way I can play the white key with my thumb tip and the black with the fingerprint, almost pushing the black key from its side. This is not that hard (although it's very difficult to explain!).
The other case is a bit more troubling, and although I have some ideas, I've started to have second thoughts on this "technique", and so I decided to ask for help here.
Is this the right approach? do you have more info on this? does this even have a name?