Good music adds a lot to a game, but only if it fits the action occurring on screen. Badly chosen music that doesn’t match the feel of your game, or is inappropriate for the tone of the gameplay, won’t do you much good. Dynamic music is one way to help make sure your music is always a good fit for the action occurring on-screen – it lets you adapt the music the player is hearing based on what’s happening.
There are various approaches for building dynamic music – some games go so far as to create hundreds of short music ‘snippets’ and string them together to create longer, more dynamic songs that never sound the same to the player once. Unfortunately, this is pretty complicated to do, especially if you’re just working with XNA and XACT. Luckily, there are some simpler techniques you can use to build dynamic music.
Below, you can see a short video clip showing one of my experiments with dynamic music. I’ll explain how it works in this post, so you can apply the technique to your games. In this video clip, I have two music tracks playing, and control the volume of one of them depending on whether or not the player character is within the blue rectangle. You can hear the track fading in and out as he moves.
The approach I’m using works like this: You take a song that you intend to use in your game, and in an audio tool, split it out into multiple wave files, one for each ‘track’ that you want to have control over. Depending on the complexity of your song, you might just want to split it out into a pair of tracks, and fade one of them in when you want the music to get more intense. If your music is more sophisticated and your gameplay has lots of variation, you may want lots of tracks that you can control individually based on what’s happening – fade in some anxious-sounding strings when powerful monsters are on screen, and temporarily fade in some ominous-sounding bass notes when the player is injured, for example.
