Why did the Leaf Village invite the Village Hidden by Sound for the Chunin exams? I am currently watching Naruto Shippuden and just watched the episode where in the past, 


   Orochimaru said to Kabuto that he is going to create the Village Hidden by Sound.


My question is, if the people from Konoha (Hidden Leaf Village) know that


   the Sound Village is Orochimaru's village,


then why did they invite ninjas from the Sound to compete in the Chunin exams? Was it not common knowledge that 


   Sound Village was Orochimaru's village?


If this will be answered further in the Shippuden then I will watch it, but I don't see why it would be.
At the time of the chunin exams, Konoha was unaware the Sound Village was built by Orochimaru. While Kabuto was infiltrating the exams as a Konoha genin, he mentioned the village was quite young and little was known about it. 


  
  Naruto Chapter 39


As for why the sound genin were in Konoha, the chunin exams became open to all villages as a result of the Third Shinobi War. Given how the Sound Village was unknown to be Orochimaru‘s cover and appeared to be an average - albeit young - village, nobody though twice about genins taking the exam.