I think a good alternative would be to create two separate awards, one for Original Music and one for Audio Design, which would encompass both sound effects and non-original music. Even if a game does not have original music, a lot of skill and work can also go into finding the appropriate tracks that fit with the mood/gameplay and using them to enhance the experience. For example, half the music in our game was written and performed by myself while the other half was made up of public domain classical music performances and songs from the 1920s, and the task of curating/choosing those specific tracks and not others, as well as making them work in key moments of the game, took months. But like I said above, this might perhaps be better classified as "audio design" and it would be fair for it to be acknowledged in a separate award.