The piece is Liszt's Heroischer Marsch im Ungarischem Stil, S.231, and the passage is this (measures 57-64). Notice how irregular the beaming is in the right hand, going across barlines and grouping together some notes whilst leaving others stranded.
At least three versions of the sheet music use this same beaming.
Note that all of the 16th notes have the same duration; none of them are hidden triplets (like in ms 55). I am having a hard time interpreting what this signifies. My only explanation is that it is meant to show phrasing; that you should really feel and express the melody as groups of 3, 3, 4, 1, 4, and 15 notes whilst playing the melody.
But several sources call beaming for phrases a "common error", or establish really strict beaming rules, all in the name of readability. So well, why'd Liszt do it?
Is this phrasal beaming:
- a highly unusual thing for Liszt to do (as we know him for).
- something common in Liszt's time that's discredited now.
- something that, as far as the method works go, young music students need to be discouraged from doing as they are likely to go nuts with it; whilst only experts know how to properly use phrasal beaming.
- not at all phrasal beaming but something else.