A few years ago, I did some work on the Stadium Hero driver after "Siggy12" reported a bug that it always played "Stella" during gameplay. With the fix I put in, the in-game music is properly randomized. However, after finding the 68K code that implements this, I thought it might be useful to provide a way to force-select a particular BGM track. The XML below is what I came up with.

Code
<mamecheat version="1">
<cheat desc="Select BGM">
	<parameter>
		<item value="0x00ea">None</item>
		<item value="0x0000">Paradise Spirit</item>
		<item value="0x0001">Hurricane</item>
		<item value="0x0002">Escape</item>
		<item value="0x0003">Stella</item>
	</parameter>
	<script state="run">
		<action>maincpu.mw@0017e4=103c</action>
		<action>maincpu.mw@0017e6=param</action>
	</script>
	<script state="off">
		<action>maincpu.mw@0017e4=0200</action>
		<action>maincpu.mw@0017e6=0003</action>
	</script>
</cheat>
</mamecheat>