Yes, you got me there . Imsevimse is chosen to give the chills to Sweds at this forum that are afraid of spiders and there are a lot of people afraid of spiders. The username could be translated to "itsybitsy" as the same song also is known as "Itsy bitsy spider".
You are right the Swedish folk songs lend themselves to harmonic variations. Jan Johansson was a great jazz pianist who made some remarkable recordings where he merged the Swedish folk songs with American jazz tradition and created a new dialect that later Swedish jazz composers like Nils Lindberg and others continued. If you've listened to Nils Landgren he sometimes includes some Swedish folk songs into his tromboneplaying. Nice that you arrange these traditional folk songs for your family choire.
What I'm I doing? I'm having long walks in the forest every day. I've got to do a change to improve some minor health issues. Not to late to do a change, but it has to be done now. I will se what the doctor says in August. My walks last between one and two hours and I have beautiful surroundings here so I can not complain. I've done them for about a month now. Since April I have also put myself on a diet. I'm beginning to get the reward as I can feel the health improved. Other things I do is to work on my house and of course I play a lot with my trombones. I've had a few weeks of vacation which are going to end soon. I will do a concert with the "Johan Stengård Jazz Big Band" at a jazz festival on Saturday and then life will return to normal again as a computer programmer and tromboneplayer.