Yes, you can "re-key" it to work with any key that will insert into the lock. The problem is, Yamaha used up to 4 or 6 different key styles. Some offset left, some right, some had narrow grooves down the sides, some wide. You need to find the style that will insert into your lock.
The lock cylinder itself uses spring-loaded sliding plates as "tumblers". The top 4 or 5 engage the key and work the lock. They have rectangular cut-outs in them for the key to pass through. The height of the cut-out determines what key notch they work with. The one at the bottom locks the cylinder into the housing. You need to reach down into the bottom of the lock with a pick of some sort and slide that bottom plate over to release the cylinder from the housing.
Once you have it out, you'll notice that all the plates stick out one side of the cylinder. Inserting the right key will pull them all down flush so the cylinder can be turned. The wrong key may pull some flush but the rest will still stick out above or be pulled too far and stick out the bottom.
If you're lucky, you can just swap some of the "wrong" plates around and things will line up. If a plate pulls too far, you can file the cut-out larger so it pulls flush. If it doesn't pull enough, you need to replace the plate or remove it completely (leave it out).