Technically, the first is less difficult than the second, which in turn is less difficult than the third. However, even producing the quality forte, dance-like sound in the first movement is no easy. I don't even think of gambling with this piece in my fellowship exam. However, Stravinsky's Serenade in A is relatively easier, technically. Perhpas it's only my personal problems: I don't have big hands, and I'm 40+ years old (not practising music as my career).How long a 20th century / contemp piece do you need? 5+ minutes?