In the old iTunes days, both podcast episodes and music tracks were available when creating a playlist. (I like to mix things up when going for a run without having to manually switch things around in the middle of running.)
How can the same be achieved using the new applications (Music, Podcasts etc.)? Are there alternative ways?
~/Library/Group Containers/243LU875E5.groups.com.apple.podcasts, so you can search for .mp3 files within that and drag them onto the Music app. (Podcasts mangles the filenames, but the tags are all present so Music sets most of its metadata fine.) I'd be interested in a proper way to do this, though…