Magically after writing my problem I think I found the right reasoning.

You can order the Classical pieces in 3*2*1 = 6 ways

The Romantic pieces in 4*3*2*1 = 24 ways

The Contemporary pieces in 2*1 = 2 ways

You can order the genres in 3*2*1 = 6 ways

Total number of ways = 6*24*2*6 =1728 ways

Right!? :P