• move
• capture
• check
• game victory
• game defeat
• game draw
• tournament victory
• tournament second
• tournament third
• tournament lower ranking
• tournament start count down (10, 9, 8, ..., 1, go!) ideally one file per second (for people who join like 4 seconds before it starts for instance) (could also be used for tournament end)
• new challenge
• new PM
• generic notification to use in other situations that require user attention
• atomic chess explosions! http://lichess.org/tv/atomic
• clicking the Berserk button (half the time on clock, on more tournament point)
• low on time

and anything else you can think of!

If you want to, we can have several sound themes.