Using stereo music

How does one add a stereo music track? This is not a video of musicians recorded in stereo; rather I want to add an audio recording that is in stereo as background to video and narrative. I know I can reduce the music to mono and add it on an audio track, but I would like to keep it in stereo.

2-channel import should be just fine, you only see one audio track but it doesn’t mean stereo it is reduced to mono.

That’s helpful, but now I’m confused about a related matter. In addition to needing to work with a stereo music track, I have video recorded using one mike on track 1 and a second mike on track 2 – two people in an interview setting, but functionally stereo. When I work with the video, and chose one or the other in audio properties, I can hear only one mike. How would I achieve a mono output (center in stereo terms) of a conversation between the two people?