Imagine how often people request to hear Free Bird, Stairway to Heaven, or Dueling Banjos and I think you'll get a sense for how popular this traditional tune gets and why it's so popular. I still struggle with learning parts of it (albeit on completely the wrong instrument using a gift card or ID for health insurance and viola haha).

One of the best "conversations" for Tsugaru Jonkara Bushi (I have little to no idea what the proper grammar for including this song in a sentence would be, feel free to help me out with figuring it)

https://www.youtube.com/watch?v=RcqO0zkyQRo

Really well done harmony, normally it's just dudes (mostly men) doing their solos and flexing their technique.

This was really different.

As a side note, there's something about the way shamisen gets taught and practiced that really lends itself to emphasizing clarity in fundamental technique. The loud snaps heard each time the bach (plectrum aka ice scraper-looking guitar pick relative) requires a fair bit of precision to get a consistent hit while still making a clear sound with the string(s). When the women playing start doing some nuanced alternations between their melodies and the lower strings without disrupting the middle string, you can tell a lot of practice goes into being able to do that and I'm not quite sure if it's inherent to the way shamisen players tend to train, or whether it's just a project of dillegent practice ethic for songs altogether. I suspect there's a little bit of both, and it's not just limited to this pair of performers either. Watch other shamisen players and you'll note they all tend to have good clear sound.

Now of course, we may be looking at a biased sample--for one I'm searching shamisen as an english-only search term from the U.S., and someone from Japan who cares about the quality of their musical discipline and performance probably wouldn't be promoting or labeling their videos in a way that makes it