What happened when Zach showed the others how he could tap dance?

Whe Zack agreed to dance, Willie became one of the group again..... he was no longer seen as different.

From the text:

All the sudden admiration unnerved him. He felt lonely being so different. To hide his fear he asked Zach to tell a joke and do his funny Buffalo step. Zach hesitated at first, but luckily someone who hadn't seen him do any tap dancing egged him on. Willie was soon forgotten and became mixed into the group again.