This is the "Musical" (*cough) Stihl chainsaw. It's just a silly short clip with some failed video editing. Had it worked out as planned, the video would have had the bar of the saw rise and fall in time with the "Music" (*cough) but during the compile process the edits all bunched up at the beginning and so failed. Well, it was fun to try anyway. Never be afraid to fail, if at least you try.
If you guys like chainsaws make sure you check out Dan's channel at @KainKustomGarage He has some sweet running and sounding classic saws. Lots of the old Jonsereds, Homelites and McCullochs on his channel. You may notice a sweet Street Rod or Classic car every now and then too.