Pass parameter to EventHandler [duplicate]

Timer.Elapsed expects method of specific signature (with arguments object and EventArgs). If you want to use your PlayMusicEvent method with additional argument evaluated during event registration, you can use lambda expression as an adapter:

myTimer.Elapsed += new ElapsedEventHandler((sender, e) => PlayMusicEvent(sender, e, musicNote));

Edit: you can also use shorter version:

myTimer.Elapsed += (sender, e) => PlayMusicEvent(sender, e, musicNote);