For sounds, it doesn't really matter if it's a digital audio recording or a MIDI thing, sound is sound and you play them the same way.
(Note that gTheMusic itself resolves to a Sound instance, just like openDoorSound is one.)
The main difference is in how exactly the digital audio tracks are stored: In older SCI, they are part of the sound resources as a special kind of track and the big issue is how to insert such a digital audio track. This is how for example Roger can audibly think to himself "where am I" in the Space Quest 3 intro movie.
In SCI11 and later (perhaps SCI10 too but I'm not sure) there's separate audio resources. If there's a Sound instance like openDoorSound set to, say, number 103, and you tell it to play, the interpreter will check if there's an 103.aud resource and play that instead of 103.snd.
So if you were to open Space Quest 3 in SCI Companion and look at sound 100, you'd find a single "D" track that you can't play. If you look in SV instead, you see it has a digital track, 11khz, 8 bits mono, and you can play it. These are hard to replace but I managed it some time ago (I surprised myself when I pressed play and heard myself ask "waar ben ik"). These sounds can also have both digital and MIDI tracks, like SQ3 sound 74. If you look around the forum well enough you may be able to find the tool you need.
If you open Space Quest 5 instead, you'll see SCI Companion now has both a Sounds tab and an Audio tab. The side bar explains exactly how easy it is to import digital audio. Sound 202 is an explosion which is available in digital and MIDI versions, while #102 ("D'oh!") is digital-only.