Of course, this assumes that the flood preceded Neanderthal. As I said in my other post, the placement of Neanderthal is quite important to the Biblical Chronology. Apes and beings with no aesthetic sense do not make musical instruments.
Mankind is the only being who makes musical instruments.
Surely Adam must be prior to a man who makes a flute. To answer this, you need to know what rocks the flood deposited. If you can not point to a set of rocks and say 'That is what the Flood did', then you have nothing. The only place I can find anything that remotely matches the Biblical description is the infilling of the Mediterranean Sea, 5.5 Myr ago. The geology clearly shows that the sea was a dry desert and in a geologically instantaneous moment, it was deep, deep ocean.