I'm assuming a similar process here.
What you're gunna want to do is infact get a music loop. Take that music loop, even if stereo, and put it into the music folder obviously.
Launch Blockland and go into Start A Server, and select it the music, but dont start the server. Start a DEDICATED server. (ONLY IF ITS A STEREO .OGG KEEP IN MIND)
Once thats up, Blockland will allow a stereo .ogg through.
Get into the game, and get your event-hat on. Once the player enters the area or something, make the music brick (which shall be hidden) play the sound, and once they find it out, then make the event stop playing.
If you are strictly going for a sound effect, I'm afraid you'll have to mess with the sound effect for how long you want it to play, and stuff, then put it into the game.
(also, knowing furling, you'll have to have an extra event that does something to signify it works, such as something changes color. but change that after you know it works.)
If you guys are going to fight over why he's doing this wrong you can at least TRY helping him with instructions.