Its hard to say what is causing this, because you're showing only a part of the action.

The if conditions might become false after you move the player to his new position, and the whole function stops until you move and turn the player and then continues, possibly hitting some other snd stop instruction...

This conclusion comes from the fact that moving snd_stop out of the if conditions plays the music before he reaches the desired height and after the turning took place...

I hope this helps

EDIT*:
You could try renaming your snd handle to something else, for example eventMusicHandle, this way it wont be stopped, until it finishes, because no other snd_stop instruction with that handle exists...