can someone help me with synthizer?

hi:
as i can't register to the audio games form: so i will post that here
i started out with synthizer: and i playd with the examples a bit. but i can't play a sound mor than one time. for example: a footstep it plays only one time: then i can't play it again.
i have tested the following things:
typing source.play() 2 times: not working
trying to remove a generator then adding it again: not working to
any one can help?

is it python?

yes it is python
and finaly i got a audio game from account bye the name of haythem