I’ve often watched videos on Youtube which are cut together to show the musician performing each of the instruments in the song. Two notable musicians who are very good at this are Julia Nunes and Jenny Rafferty.
I think the usual way of making these types of videos is to use editing software and mixing the vocal tracks using the program. I filmed myself with iMovie recording each track with garage band (I wasn’t going to use a mixing desk as I don’t really record covers. they’re just a Youtube thing.) I then matched up the videos with the finished track and cut it together fairly randomly! Sometimes getting everything in sync feels like more trouble than its worth but because I can hear the actual singing in the videos, its fairly easy to match up.
Hope you like. I welcome suggestions for songs which you think I should ‘Get Frank’ up