mixing mono and stereo tracks

i am using Audacity 2.2.2 on a windows 10 computer. I am creating a recording of a meeting into which I have to insert some music, replacing some recorded passages. The problem I have is that the 1 piece of recorded music that I downloaded is a mono track and unless there is another way to do it it will not accept my method of patching it in. Thus far I have been loading the new music, cutting the content after where it must be inserted and pasting it on to the end of the new music and then re-pasting the whole lot back onto the end of the original recording from where I cut it. Cumbersome I know but the only way I can make it work, that is until I tried to paste a stereo portion onto the end of a mono section,
has anyone got a bright idea or some experience with what I am trying to do.

thanks,

Leave them on separate tracks, and they will be mixed to a single stereo track when you export.

And if you get really fancy-pants, use the Time Shift Tool (two sideways black arrows) to overlap them a little and use the fade tools (Effect > Fade-In and Effect > Fade-Out). Pick the last few words at the end of a sentence and gradually Music Up.

Koz

Thanks Steve. The next question is “How do you create that gap for the pasted bit to slot in?” know I am not very versed in handling Audacity but I am slowly learning.

To make a gap, you first need to “split” the track (see: https://manual.audacityteam.org/man/edit_menu_clip_boundaries.html) so that it becomes two separate audio clips, and then drag the clips apart using the Time Shift tool.