"I know I'm not the only one to find the notion that a 15 year old is claiming to have learnt most of the 2nd Hungarian Rhapsody in a matter of days."
Its actually not that hard. I learnt it in all by memory and could just about play it in a week age 14. Its very repetitive, so is not hard on the brain. If you harmonically reduce it, the lassan is easy to get in your brain. WATCH THE PASSAGE with scales and jumps at the end before the cadenza - VERY risky, if youre tired. Leslie Howard says it is one of Liszts nastier passages. Practice the left hand jumps with your eyes closed (I can still hit them after not touching it for a year). The scales in the right hand are risky, it is easy to bollocks them up. The trick I found (I play it very fast) is to play the scales lightly and not trying to make it legato, and whip it off at the end (Leslies method). The end of the F sharp major one, finger it 12345 so you hit the top on five. start the run with 123 then play nromal F sharp fingering.
Still, if you can play this piece well enough to perform it in 4 days age 15, I am very impressed. Bravo.